Very positive reviews:

The Telegraph:

To Walk Invisible was not what costume drama normally looks like when it worships at the altar of literature. Wainwright took as her beacon the dauntless and free-spirited Charlotte, Emily and Anne Brontë. We think we know their story – pseudonymous creation and tubercular death.
These bare bones acquired flesh anew as the three sisters in their brother Branwell’s famous triple portrait were brought to fizzing life, equipped with robust Yorkshire accents and a furtive but furious determination to be heard. (...)
A sense of what it must have been like for the public to come upon these unknown authors was cannily recaptured in bold casting. None was played by an obvious household name. Finn Atkins’s Charlotte was a pugnacious pocket dynamo, Chloe Pirrie’s lanky Emily a clenched fist for whom words were hard as nails. Charlie Murphy (familiar from Happy Valley) was lovely as Anne, the delicate counterbalance to these warring alpha females. (...)
There was admirable economy in a narrative neatly patched together with letters and flashbacks. Wainwright spurned the chance to name-check Heathcliff and Cathy, blind Rochester and the madwoman in the attic. This was not about them but the forces that created them.
Her other omission was to end before the end, with Branwell’s release from torment, and relegate the deaths of Emily and Anne to a neutral postscript. She spooled forward instead to the present day when tourists in cagoules buy Wildfell Hall fridge magnets.
The point is that early death is the least interesting – the least wuthering - thing about them. Three cheers for these three sisters. (Jasper Rees)

The Guardian:

To Walk Invisible (BBC1) concentrated on what historically has been – for reasons of taste and delicacy early on, and later because of the obfuscatory nature of the gathering myths – an underacknowledged aspect of the three extraordinary years in which the sisters wrote the books that would make them famous, which is that they did it all in the teeth of their alcoholic brother Branwell’s brutal decline and death.
This, of course, is Wainwright’s specialist subject – the extraordinary things ordinary people face and the courage it takes to surmount them. She takes for granted the sisters’ genius (the books, after all, are there to prove it to us), leaving the focus on the domestic tyranny exercised – ’twas ever thus – by an addict in the family. (...)
To Walk Invisible was, above all, true to Anne’s heartfelt plea in the introduction to the second edition of Wildfell Hall – for people to abandon the “delicate concealment of facts – this whispering, ‘Peace, peace’ when there is no peace.” It was bleak, beautiful and brilliant, like everything Wainwright and her growing repertory company does. (Lucy Mangan)

Positive:

The Times:

Did the Brontës ever say “at it”? Or “f***”? Of course if you read their letters — or for that matter Jane Eyre — they seemed to think of little else. “If you knew my thoughts,” Charlotte wrote breathlessly to a friend, “the dreams that absorb me; and the fiery imagination that at times eats me up . . . you would pity and I daresay despise me.”
History and the Victorians asterisked all that out, turning the Brontës into the sort of paragons of probity whose catchphrases shift notebooks in cosy northern gift shops. Here, Sally Wainwright put the f***ing back in, in every sense. She also added a fair bit of other stuff that wouldn’t do so well on notebooks. It was advisable not to be eating during the vomiting-blood scene. (...)
The actors and script were excellent. Wainwright is perhaps best known for Happy Valley and there were shades of that here. At one point the hopeless Branwell became more troublesome than usual. Emily Brontë intervened. “If ’e ’its me,” said Emily, “I’ll ’it ’im back. ’Arder.” Sgt Cawood would be happy to have her in the team. (Catherine Nixey)

The Arts Desk:

Yorkshire-born screenwriter Sally Wainwright has carved a distinguished niche for herself as chronicler of that brooding, beautiful region’s social and familial dramas. After the romance of Last Tango in Halifax and the gritty panorama of Happy Valley, she has settled on perhaps the quintessential troubled Yorkshire family, with awesome bleakness on the side: the Brontës.
Despite a difference of 150 years in setting, To Walk Invisible is not only a seamless progression from Wainwright’s previous work, but the story comes, ready-made, both achingly sad and also driven by a passion that can’t fail to uplift. Much like one of the sisters’ novels, in fact. So while the source material is already very rich, the narrative has been sculpted to perfection, with the sisters’ rise counterbalanced so poignantly by their brother Branwell’s decline to first alcoholism, then
tuberculosis. (...)
Such strong roles and a taut script were a gift to the actors. Of particular interest was the contrast between the feisty, family-centred Emily (Chloe Pirrie) and the cooler, career-focused dedication of Finn Atkins’ Charlotte. Another star of the Brontës’ fiction, the countryside, only made brief appearances, and it would have been interesting to find out more about how the solitude, space and quiet became an invaluable part of the writers’ lives and works.
Otherwise, the only jarring note was the ending, which faded to Haworth Parsonage as it is today, all cream tea and Christmas cards. The purpose, presumably to ground the setting in our present-day appreciation of the sisters’ work, was fine and sensible, but the effect couldn’t help but be anticlimactic, after such a tense and finely-poised tragedy. (Matthew Wright)

Den of Geek!:

Wainwright is aided by an extraordinarily strong cast, particularly in Atkins, Pirrie, and Murphy as the three sisters. They disappear into their roles effortlessly and have an easy rapport with each other, without losing the tension that is always underlying when siblings live in close quarters. Murphy has the less showy role as the quieter Anne, but she does a lot of the emotional heavy lifting in the background. Atkins’ stoic Charlotte is the stern centre of the piece, her steely ambition driving the sisters forward and she is scarcely seen without a furrowed brow. But it is Pirrie’s Emily who stands out the most, a tempestuous, passionate figure who vainly attempts to keep her brother with them and whose poems are the inspiration behind Charlotte’s publication plans.
For lovers of the Brontës’ work, To Walk Invisible is a gift, carefully constructed to capture the voices of the pioneering women at its heart and the spirit of their work. It is a fitting tribute to the passion for the worlds they created, as well as acknowledging the personal and social obstacles they had to overcome. (Becky Lea)

Lukewarm:
Radio Times:

The drama is also peppered with brilliant performances, from Jonathan Pryce’s genial yet haunted patriarch Patrick Brontë and Nagaitis’ charismatically pathetic Branwell to all three sisters. (...)
However, Wainwright’s passion for the subject matter is also the drama’s weakness. At two hours the story feels indulgently long, and seems to assume a certain level of Brontë knowledge from its audience lest they be left behind (a lot of references to the young Brontë's juvenilia fall into this category).
Dramatically, by contrast, certain scenes feel the need to hold the audience by the hand, with characters delivering emotionally expositional dialogue about their struggles as women in a man’s world that feel a little on-the-nose for writers who wrote with such subtlety. (...)
The end result is a well-acted and unusually historically accurate drama that just feels a little overwhelmed by the responsibility of doing the Brontës and their legacy justice, culminating in a slightly bizarre segue to the present day Haworth Parsonage which serves as little more than a plug for the gift shop. It has some excellent qualities, but overall To Walk Invisible is not quite the full Brontë. (Huw Fullerton)

the Brontë Sisters:

Beautiful walks on the moors.
I loved the meeting between Anne, Charlotte and George Smith and William Smith Williams. I always love this part of their story and it is beautiful filmed.
I wonder, if you don't know much of the Brontë Sisters and you see the movie, will you understand them better? Will you understand what they mean for literature?

Radio Times also asks readers to share their thoughts on the production.

WTF:
The Daily Express has one of its usual tantrums and using the extraordinary and amazing investigation of method of searching on Twitter, it finds four tweets (we have looked too and we have found a couple more) of people complaining about the sound quality. This is journalism at its best:

Many (!) of those tuning into To Walk Invisible last night were left disappointed when they struggled to understand what was being said in the period drama.
However, many (!) viewers were far from impressed with the sound quality of the two-hour special and took to social media to slam the "inaudible mumbling". (...)
Despite the complaints over the sound quality, others [over 700 tweets] tuning in praised the Sally Wainwright penned drama. (Helen Kelly)

Radio Times also looked into Twitter and found that the vast majority said quite another story:

Sally Wainwright’s bleak drama about the Brontë sisters, To Walk Invisible, got the thumbs up from viewers on Thursday night.
The two-hour programme, written by Happy Valley's Sally Wainwright, told the story of the last three years in the lives of the siblings who took the literary world by storm in the 1840s from the wind-blown seclusion of the Yorkshire parsonage where they lived and worked. (Ben Dowell)

Other related articles:

The Independent discusses Chloe Pirrie's role as Emily Brontë:

Pirrie was surprised to discover that Emily was someone who struggles with interactions, until she puts pen to page, and that she was a bit of a homebody. To Walk Invisible concentrates on the family dynamic of the sisters and their relationships not just to each other but also the men in their family. The family dynamic, Pirrie discovered, even affected the clothing choices of her character, which are quite extraordinary.
“Emily was stubborn with her dress sense and would choose stuff that clashed,” explains Pirrie. “She would wind Charlotte up by wearing things that didn’t go together.”
This all added up to Emily being the type of character that Pirrie is making a name for herself being: the outsider with an edge. The actress says of the roles that she’s been landing, “I feel like your quirky dish.”  (Kaleem Aftab)

Radio Times highlights James Norton's brief role as Duke of Wellington and the other supporting cast:

Early on in the story younger versions of the Brontë siblings are playing a game where their toy soldiers seem to magically come to life – and the mini-Duke of Wellington is none other than Norton, reuniting with To Walk Invisible’s writer/director Sally Wainwright after making his name in her critically-acclaimed BBC drama Happy Valley.
And clearly, the Happy Valley loyalty to Wainwright runs deep, with several other actors from the Bafta award-winning crime series popping up in small or cameo roles.  (Huw Fullerton)

British Telecom interviews Sally Wainwright. Evening Standard covers the who, where and when of the production. Dagbladet (Norway) has an article about his production. AnneBrontë.org focuses on Anne's portrayal.

Some other stuff:

Movie City News reviews Andrea Arnolds's Wuthering Heights:

She would veer away from the grit and grime of life among marginally employed Brits, into the more refined precincts of Brontë country, for Wuthering Heights. Arnold’s adaptation striped the novel of certain literary elements to focus on those aspects that lent themselves to more darkly cinematic and sensory interpretation. (Gary Dretzka)

The Guardian's Country Diary describes Ladle Hill in Hampshire:

The lightest of winds twitches the smears of wool caught on wire barbs. Up here ‘There is no life higher than the grasstops / Or the hearts of sheep…’, as Sylvia Plath wrote of the West Yorkshire moors in Wuthering Heights, her poem of exquisite introspection. 

The Daily Mail reviews Yours Always: Letters of Longing edited by Eleanor Bass:

In a series of unanswered love letters to her former French teacher, the young Charlotte Bronte complains of ‘tormenting dreams in which I see you, always severe, always grave, always incensed against me’. (Helen Brown)

The Daily Herald Tribune reviews Trainwreck by Sady Doyle:

She believes the way we gawk at these women and then delight and mock the way they fall is inherently misogynist. And it’s not a new phenomenon. Mary Wollstonecraft and Charlotte Brontë were seen to be ruined women for falling in love with the wrong men, doing things that were seen as inappropriate for women at the time and having public meltdowns. (Alexis Kienlen)

Bustle has a list of DIY hairstyles:

Jane Eyre hairstyle. Jane Eyre dresses in plain fashions, and her hair would no doubt match. In the nineteenth century, the style was to part hair down the middle and pin it back. This updo isn't difficult to achieve, and will inspire you to channel Jane's spirited and independent personality. (Julia Seales)

The Grammarly Blog quotes Villette for the use of 'sugarplums':

Have you heard winter songs or stories mention sugarplums? Is it a type of fruit that ripens in the winter? No, sugarplum refers to a number different delicacies made of a sweetener such as sugar, fruit preserves, or honey, ingredients for color, and various flavors. Look on this scene of Charlotte Brontë’s Villette.
"She had a warm seat of her own by the fire, she had her own solace in a short black pipe, and a bottle of Mrs. Sweeny’s soothing syrup; she smoked and she sipped, and she enjoyed her paradise; and whenever a cry of the suffering souls about her pierced her ears too keenly—my jolly dame seized the poker or the hearth-brush. . .and flung a liberal shower ofsugar-plums.” (Shundalyn Ellen)

Grazia Daily has a list of new year's resolutions:

But setting yourself the challenge of reading a new book every month will widen your knowledge, interests and conversation starter repertoire. And yes, it’s perfectly acceptable to hide 50 Shades Of Grey beneath a Wuthering Heights cover. We won't judge you. (Danielle Fowler)

Well, we won't be so kind.

The Stuff (New Zealand) helps you to organize your New Year's Eve at home:

You'll want roughly around 12 hours' worth of songs, and if you're particularly confident in your friend's good taste, you might even start a collaborative Awesome Mix Volume NYE playlist that everyone can contribute to. At least that way you're not solely responsible for putting Wuthering Heights on repeat. And the next time someone slyly adds anything by the Smiths, you'll know who to blame. There's no hiding on Spotify. (Myffy Rigby)

Bookriot lists epistolary novels including The Tenant of Wildfell Hall.

Süddeutsche Zeitung (Germany) talks about Patti Smith,

"Sie wurde als ein Kind beschrieben, das die Augen einer halbgezähmten Kreatur hatte, angezogen vom Unnatürlichen, mit einer Vorliebe dafür, stürmische Märchen zu improvisieren", schreibt Patti Smith in ihrer Einleitung zu Emily Brontës Roman "Sturmhöhe", also über sich selbst. Sätze, die man ermüdend finden kann. Weil Smith' Musik eben auch überenergetisch pathetisch ist, von einem teils lähmend hochkünstlerischen Anspruch getragen und die Songs zum Teil tausend Jahre dauern. Die Künstlerin als Pose, die Person wurde, und dann wieder Pose. (Juliane Liebert) (Translation)