I have gone 4 times the end of January. Great for low crowds--we've been lucky with the weather most of the time, but I've never wanted to go to a water park and we've one gone to the hotel pools occasionally.
Went once in February, avoiding holiday weekends. Same as the end of January, but got busy as Pres weekend got closer.
I've gone once the first 2 weeks of December. The crowds were greater than the end of January, but not too bad. The weather was cool (cold some days) decorations were nice. Not water park weather.
I've gone once the very end of Sept-the beginning of Oct. Food and Wine Festival was fun, went to the Halloween Party. It was very hot--water park weather. We went right aftera hurricane, however, which is the big risk that time of the year.
I've gone once in mid-May, which was nice. It was hot, not too crowded, but not real slow like January.
We went once in August, which of course was hot, but we had gone the previous January and were going back for more of the hot weather stuff, water parks, shows, etc, so it wasn't so bad.
I've been to Orlando and gone to Universal a couple times in April and one year had coolish weather, so even when you think that it would be warm it's not always real warm.
Hmmm, I think that covers my trips.
I'm going week after next and am looking forward to some warm weather in the beginning of May.