I've stayed at POP several times (Janx1, Mayx3, Septx3, and Decx2) and also at AS Sports (May and Dec) and AS Music last Sept. Even though POP only has the one bus stop, to me the All Stars have always had better bus service. Going to the parks I have never had to stand on an All Stars bus and coming back from the parks I've only stood a few times. The buses at the AS also seem to come faster than the ones for POP. If you stay at AS Sports you will be the first pickup and the first drop off which is very nice.
FYI: I've also stayed at POFQ, CBR, CSR, WL, AKL, and BW. The worst bus service we've ever had was definitely at BW and CBR. The best we've had was at CSR (even though we did not particularly like the resort).