My youngest turned 3 in June and I try to lay him down for a nap every day. I try to put him down at night between 8:30 and 9 and he sleeps for about 12 hours. . His Naps during the day can be anywhere from 45 minutes to 2 hours.
First of all, it is great for him and his little body but also wonderful for me to get a break in. I can do work on the computer, clean house, eat lunch, etc.
I have researched this topic alot and many people say that everyone could use a nap during the day. I know that if I had time, I would too. There are also some that say toddler do not need a nap.
I feel like they do need it. My son starts to fuss and not act himself during the day, so I know he needs to lay down. You know, they still make preschoolers and Kindergartner's lay down too because they work so hard during the day.
I'm telling you, my son works real hard during the day and needs his rest too.

It basically comes down to your own opinion. You know your child the best and what his or her body needs.