We've stayed at Pop, AS Movies, and AS Sports and been fine with all of them. I have to say I'm surprised when I hear people calling Pop laid back or relaxed!! We found just the opposite. The Pop resort is HUGE. There's 1,000 more rooms at Pop than at any one of the All Stars. So to me, the food court was always an absolute zoo. Nothing laid back or peaceful about it. People will also talk about the busing situation being better at Pop. Again, we found the opposite. Yes, All Stars will share SOMETIMES--not all the time. Not at the busiest times of day--park open and close. While Pop does have dedicated buses, they also have a TON more people vying for those same buses.
As for the rooms and decor, they're all pretty comparable so that just becomes a preference thing. Check out pictures and see which you think is more appealing.
But I agree with PPs. If there's any way to swing a stay at POFQ instead, it's SOOOO much more quiet and quaint than any of the values. I know that's not always possible, but something to think about anyway!