If it were me, I'd upgrade to a mod. The better accommodations, buses, and dining plan seem like they'd be a better value for my money.
I know I'm going to be in the minority when I say this, but I stayed at ASMu and I *hated* it, as well as the other All-Stars. They looked run down, the food court was a messy disaster all the time (especially the drink station), the pool was quite foul smelling (especially the kid section), and the bus rides to everything but AK were long. Speaking of the bus, we had to share with the other values, so at the beginning or end of the night, the line was far, far, far longer then any other resort and we waited, at times 45 minutes just for the bus. And I found the guests as a whole to be the rudest, most inconsiderate, and most poorly behaved. It will live in my memory forever the woman who was in the face of a lifeguard and screaming, I mean SCREAMING, at the top of her lungs because the lifeguard had the nerve to yell at and eject from the area her son... Who had dropped his pants and peed against a tree by the pool. The constant battles over the refillable mugs was another one I saw constantly. People were just rude and the staff just seemed generally beat down. In fact, there was an issue when we checked in where they gave us a dirty room and, after returning 5 hours later to find the room still dirty, we were told that they just couldn't clean it right now and gave us a different room.
I'm not a hotel snob by any leap, and when I booked I wasn't expecting a Hilton. I figured that, since we spend very little time at the hotel, it wouldn't be a big deal. By the end of day one, I was ready to rebook elsewhere. Now when I hear people say "it doesn't matter, we aren't at the rooms that much" I can say that it matters more then you'd think. We weren't at the rooms very much either, but the whole experience at All-Stars took us right out of our feeling Disney magic.
That said, we stayed at Pop and *loved* it. I loved Pop, and while that's slightly more expensive then the other values, the location is better, the food court is better, the property as a whole is better... It's just a better hotel. Our time there was fabulous and we looked forward to going back to the hotel at the end of the day. And the food court is awesome.
If you want a better stay without the expense of a full upgrade to a mod, Pop may be perfect for you.