We were there the first 10 days of Feb this year - the weather was nice, still a bit cool some days (needed a jacket/sweater), but there were several days we spent by the pool.
Crowds weren't too bad, except that we hit some kind of cheerleader competition, so for about 7 of the days there were swarms of teenage girls all over the place. So you might want to check on when that falls before you go. It still wasn't horrible, but we were used to just walking right on the rides at that time of year and there were lines at times on the more popular attractions.
Generally, as long as you avoid the holiday weekends, it's a great time to go.
Lin