Here's my opinion on this one, go with whichever theme you prefer, whichever is cheaper, or where the rest of the group is staying. Having stayed at both, they are very similar. I see all these Pop lovers on this board and personally, I just don't get it. I haven't stayed at AoA yet but the all stars and Pop to me are identical except slightly different theming. The rooms are the same size, they have all been recently updated (with movies being the most recent late last year). The comment about the all stars being outdated and neglected is just plain silly.
To me, the food courts are very similar. All have pools that play games, all show movies at night. I will also say that the bus sharing at the all stars is very exaggerated on these boards. I personally found that in the early 2000's they shared much more than they do now. Every stay we have had recently they have had their own buses in the mornings and at park closings and only sharing during low times during midday. While Pop has dedicated bus service, it's a large resort and the buses are busy. Dring our last stay there they were always filled to capacity and we left people not able to get on. It happens sometimes.
That's about as honest of a review that I can give from someone who has stayed at all of them and doesn't have much of a preference either way. I have a slight preference toward the all star resorts because of their size, being smaller and easier to manage with movies at the top of my list. I find pop a little large and spread out for my taste but I would certainly stay there if the price was right. It's usually a slight bit more to stay there and I don't want to pay for a preferred room so my most recent value stays have been at the all stars.