We were there this Columbus Day week and it was much more crowded than our previous visits that week (back in 1995 and 1993), although that was before we had kids so we didn't have to do the kids' rides back then. We did take the kids in March 2002 and it was a lot less crowded.
That being said, it was certainly a lot of fun. Here is what I remember that might be useful to you:
- We went to MK twice on early opening and that was a BIG mistake. The park was extremely crowded by 10:30, and, because Adventureland did not open when the rest of the park did (I think early entry was 8, the park opened at 9, but Adventureland opened at 10), all of those rides were packed right away. On other days when we park hopped back to MK on a non-early opening day the crowd was a lot lighter.
- We went to AK for early opening once (8 AM) -- again, a big mistake. It opened for all at 9, and by then the Safari line wait was close to 45 mins. It was even hard to push the stroller in the crowd. We couldn't get into the Lion King show when we got there about 40 mins early. We came back a different (non-early entry day) and they were still seating people for the Lion King show (I think we went to one around 2 PM because I recall my daughter napped at the end of it), and they were still seating people just minutes before the show began. I don't even think that it was at capacity when the show started, although it was full. We caught the Safari ride at about 4 pm with NO WAIT.
- We went to MGM and Epcot on non- early entry days and the crowds were light, particularly at most of Epcot (except for Mission Space and Test Track, but we just stood in line for one and got Fast Passes for the other). I do remember that MGM was more crowded the 1st day that we went there (but I don't remember what day of the week it was), than it was on our 2nd day there, which was the Saturday after Columbus Day.
- We went to Blizzard Beach twice, both times around 2:30, and it was not crowded at that time, although I only did the kids' area and the lazy river with my 4 year old. My husband took our 6 year old on some of the slides and said the waits were not bad.
Hope this helps! We had a terrific time and I hope you do, too!