Hey Debee~
we went two years ago and will be there this year again. I didn't find it extremely crowded... but I took into consideration it WAS a major holiday. We arrive Wednesday morning and leave late Sunday.
We didn't have to wait long for buses, monorails, rides etc. We always got a fastpass when we could. Last time, we went to Epcot on Thanksgiving day last time and then to MK later at night. This year we're doing MGM and MK later again.
The crowds were heavy in MK on Saturday, but that's to be expected... just remember, things are as bad as you make them. If you go in with a good attitude, most things won't bother you. If you go in expecting the worst, then the worst will happen!
If the crowds get unbearable, take a break and go back to your hotel or to another park. have fun, we'll see you in the crowds!!