Very welcome, Barbaraann, I just think that for what a Disney vacation costs you should get a quality experience. I absolutely don't believe you'll get that at Movies. For some reason it is the most popular of all values and Disney hasn't chosen to renovate it.
If it were me, I'd stay at Sports since you'll be getting a '2008 room' in 2008. Much like renting a car ... if there are two that are in my class and price and one has 1,431 miles on it and the other has 26,788 miles, you know which one I'm taking.
From a food court perspective, I like Pop best by far. From an atmosphere perspective, Music is actually quite lovely ... especially the Jazz Inn area at night.
If it were me, I'd do Sports, Music and Pop in that order. I'd stay far away from Movies.
Perhaps you should ask the grandson what he'd like? Plenty of pics online to look at. (Deb Wills' site has photos of all the resorts and rooms, although just sample rooms)