My family (Me33, DH37, DD5, DS3) loves Animal Kingdom. We spent an entire day and a half day there our last trip and didn't do nearly everything. The kids love all the characters and could spend hours in the Boneyard. I'm a zookeeper so I absolutely love the safari and the animal trails. During the off season it is very relaxing. We last went in January so heat was no issue as we were all wearing jackets.
Our previous trip was during a spring break week in April and by shortly after noon the crowds were almost unbearable, so I can certainly understand those who don't like it for that reason. I totally don't get the whole "half-day" not enough to do there thing! In Jan we had no real waits for ANYTHING and still didn't do Pocahontas, Dinosaur, Primevil Whirl, Kali (too cold) or Flights of Wonder. EE was not open yet...
I could have happily spent another day there but my (little) kids chose to go back to Epcot instead!