I like All Star Music the most. I was there somewhat recently and the difference in cleanliness and overall design between Music and Movies is astonishing.
Firstly, I recall Music having a better laundromat situation. I believe it is seperate from the actual bathrooms and showers, which makes it a lot more private and nice if I ever did have to do laundry.
Admittedly, Movies does seem to have a bigger main pool area. However I think the theming with the beach huts makes the Music area more immersive.
The Music food court is superior by far. I know it's mostly the fact that Music had a recent refurb, but I still love the Mickey annd gang artwork and the seating was cleaner. I don't remember much about the size of the seating area.