We were at MK the 12th, Epcot the 13th and MGM the 15th.
I would definately agree that the parks were crowded ... but I was very surprised at how manageable it was using EMH (AM at MK) and fastpasses.
We were at the MK gate at 6:50 AM on the 12th and finished everything we wanted to see and do by 11:30 AM. Walked on just about everything except for Space Mountain ... used fastpass here. Crowds were pouring in as we were leaving after having lunch at Casey's.
Epcot was very crowded on the 13th. Used fastpass for Soarin' ... the standby line was incredible at 10:30 am .... I think it was 110 minutes ! All fastpasses had been distributed for the day by about 11 am or so. I think some of the huge crowd at Soarin' was due to the fact that the MissionSpace death scared people away ... I think it only had a 20 minute wait that morning.
Rode Test Track standby after picking up Soarin' fastpasses and only waited 20 min ... got fastpasses to use in the evening, but when we returned the fastpass line was enormous due to the fact that it had apparently broken down at some point during the day (what a shock

) and many, many people were trying to get on using their fastpasses. We were happy we went standby early in the morning and decided to skip our second ride using our fastpasses.
Turtle Talk with Crush was the only thing we missed seeing ... 100 minute wait !!!
I will add this was a day that Epcot had EMH that evening. Several of the CM's said that they felt this increased the size of the crowd all day ... apparently many people are going with the non-hopping option on their tickets and spending the entire day and evening at the EMH evening park.
MGM was really great on the 15th. Very surprised at how manageable it was. Didn't use fastpass at all (but we don't ride TOT of RNR). I did see the wait time at RNR was 40 minutes at around 2:30 when we made a pitstop at the restroom after seeing Beauty and the Beast.
All in all, a very enjoyable trip. I would definately do a Spring Break trip again. The weather was simply AMAZING ! Even though it's alot more crowded than when we usually go (late August), it's just so much more comfortable. It's alot easier to wait in a line in the beautiful April weather than it is to sweat your guts out waiting in a line in August !

The extended hours also give you alot more options on how you can visit the parks. Early birds can get a very early start ... and night owls can enjoy the parks until the wee hours of the AM ... MK was open until 3 AM last week !
Park crowds - I'd say 7 (MGM) to 10 (MK and Epcot).
I used my own touring plan based on previous trips.
BWV was crowded ... but we loved the busy atmosphere. It was actually nicer and more festive. The evening performers at the BW were terrific !
No issues with pools or restaurants.
Just my 2 cents ... hope it helps !