We were at ASmu in September and POFQ in May of 2002...
To us, POFQ is in fact bigger with larger walking distances from rooms farthest from the main building.
ASmu had more of "Magic Kingdom" layout: Main Building, Calypso, and Jazz making up Mainstreet, the piano pool as the hub, Rock Inn as Tomorrowland, Country Fair as Fantasyland, and Broadway as Adventureland.
POFQ is more of "Disney Hollywood Studios" layout: Mainbuilding makes up the central hat location, Buildings 1 - 3 are Tower of Terror and Rockin Roller Coaster, while buildings 5-7 are the Soundstage, Star Tours, and the backlot Tour.
Basically the biggest difference is that POFQ is more horizontal while ASMu is more verticle layout wise.
Maybe it's just the building design/layout but we do feel that it's larger, but smaller when compared to Disney's other Moderate resorts. Either way the layout is very nice and offers some great rooms close to the main building and pool area. I'd say that only building in which you'd notice a considerable difference is building 7.
This would be my personal comparison:
Calypso/Jazz: Buildings 2, 3, 4, and 5
Rock Inn/Broadway: Buildings 1 and 6
Country Fair: Building 7
POFQ has such amazing grounds that the walk is that much more enjoyable! You will definately notice a more spacious difference... but in a good way!