Well, I'm back from 6 nights at Pop.
My final verdict:
I agree that it's the best of the values (this is our 3rd value). We were in room 1124, 50s section, preferred, facing landscaping. It was a super, super easy walk to buses, pools, food, etc. The room looked great. The pool was awesome. No problems at all with transportation. We've stayed at two other values previously - Sports and Music - and I just felt the general layout, look and feel, amenities, etc., were better at Pop. To me though, it didn't really feel like a vacation resort... more like summer camp. Which isn't necessarily bad, but not necessarily what I'm always looking for.
So if I did a value again, it would be Pop. But I'd prefer to stick with deluxe.
Pros:
Transportation was great. It never felt like a long bus ride anywhere. Often, there were buses double-stacked for the parks in the morning during the "rush".
Room was super nice and clean and fresh. Mousekeeping was on the ball and had our room clean by the time we came for break each day (that has been an issue for us at every other resort we've stayed at Disney World).
The pool was cool and refreshing. The main pool at ASMu was about 180 degrees. Hippy Dippy was actually refreshing.

We did use the locker room area by the pool on our final day and it was clean and serviceable.
The food court was okay. I felt there was more variety than some other resorts where we've stayed and the lines never backed up as badly as they did at the All Stars food courts.
Cons:
It was NOISY. And since there were very late park hours all week, the noise never stopped. I didn't sleep well a single night. And my son, who generally sleeps like a log, was even bothered by it. I'd stayed in a preferred pool-facing room (literally steps from the pool) at ASSports once as a free upgrade and it was super noisy, too, so vowed to never do that again. Then two years ago, we had a courtyard facing room at ASMusic in Jazz (but on 2nd floor) and it was nice and quiet. I was really disappointed by the noise issue. Mostly just disappointed by how inconsiderate people are. Surely they realize that people could be sleeping just on the other side of those windows? I agree with what another poster said though - I think it may seem quieter in a King room. Our quieter experience at ASMusic was a King room. Your head is just so darn close to the wall in the two bed rooms.
Also, really missed the poolside activities like they have at ASMusic, BC, and BLT. Since my son is an only, he really likes those activities as a way to meet up with other kids and have someone to play with other than his boring parents.
A little annoyed that they don't have towels available at the pool. Every other resort we've stayed at (including the other values) had towels available.
And one issue with the locker room by the pool: the changing area is right inside the door - which is viewable from outside when the door opens. AND when the cleaning guy pops his head in to check to see if the room is empty.

(Fortunately, I was wearing enough clothes to be decent.)