We just returned after being there from 11 July - 19 July. The crowds were manageable if you planned right. Go when the park opens, take advantage of fastpasses, take an afternoon break, and make PSs for popular eateries. We avoided all long lines.
One day at MGM the line for Tower of Terror was 130 minutes and the fastpass line was a 30 minute wait. They actually stopped letting people into the line. They told us to come back later with our fastpass. Several hours later - the standby line loaded quicker than the fastpass - five minutes at the most for both. We also went back to Animal Kingdom around 4 o'clock on the EE day. We were able to ride the Safari, Dinosaur, Primawhirl, and Kali River Rapids - we only waited in the line for Kali.
We never went to any water parks but they looked packed.
Have fun!