We were there from April 26 through May 2 and found everything was awesome. We never waited in line once (not even for Nemo, which usually has long lines) and the weather was great. It was raining while we waited for the Fantasmic show Monday night, but not too bad.
I hope the next trip we make will have the same experience in terms of weather, crowds, etc. Someone posted from that same time period and thought the parks were sorta busy - we must have been in different places each day.
WAIT! One time we waited 5 minutes for Aladdin's Magic Carpets. DH was a little bummed out ... and when we went to the Monsters, Inc. show we did have to "wait" as the people walked into the theatre.
Perfect time to go, IMO!