i like all the value resorts - as with everything there are pro's and con's
biggest pro for the all stars - buildings (even the farthest away) are not that far from the main bldgs. really cool pools. really good bus service...but sports is first on the stops in and out of the park
biggest con for all stars - the buses usually stop at the 3 resorts...and if you are movies (the last in line) i think the chances of a seat are usually slim to none.
biggest pro for pop century - bigger resort (land and room wise) so there are more CM's at the check in area, the food court is much bigger and the food court CMs will come out and do the hustle and twist etc when the music comes on while you are in the food court. theme is cute. and different music is played in the food court..
biggest con for the pop century - because the bldgs are so spread out, the distance to you room, especially after a day in the park, can seem like it takes forever. for me, you are not hearing/seeing disney every where you go like at all stars.
so depending on your preferences...any value resort is great