I'd been meaning to post an update --- thanks for the reminder!

For summer use, I love our heat-pump water heater. It operates as an Air Conditioner and dehumidifier while also heating water using much less electricity than a traditional hot water heater. We haven't plumbed the drain pipe to the outdoors yet, so I also end up with about two gallons of water to use in the garden every week --- bonus!

On the other hand, we chose to keep the unit in electric mode over the winter so we wouldn't chill down our living quarters. The particular brand we bought automatically turns to heat-pump mode after 48 hours, which meant every two days I had to push a button or end up with a cold room. So, a minor downside...but not enough to decide against the model. (Placed in an unused basement or close to an overachieving wood stove, you could likely leave it in heat-pump mode all year.)

Similarly, the noise factor might be a problem for some of you. I'd say it's as loud as a window air conditioner, which I actually found soothed me to sleep at night. (We generally only use hot water in the evening to do dishes and bathe, after which the water heater runs for around two hours to refresh itself.) For me, this was a surprising plus rather than a minus, but your mileage may vary.

The final factor is energy efficiency...and here I have to trust the manufacturers that the unit is dramatically more efficient than a traditional model. Our electric bill has been lower than expected this summer, despite running the minisplit to cool our living space quite a bit more than we ran an air conditioner back in our old place. But we also haven't plugged in any chest freezers, so it's hard to know where the savings came from.

Overall --- yes, I would totally buy another heat pump water heater. Whether I recommend it to others depends on their house layout and how they feel about moderate levels of noise.