We've stayed at both and I preferred Pop's bus service, food court and just about everything else! We stayed in the Mickey phone bldg in the 70s section and could see the food court from our window. We DID stay at Pop during a slow time in January and POR during a busy spring break week, so that probably made a HUGE difference. However, one day on our last trip (staying at Pop) my parents had the kids and DH and I wanted to go from DTD to MK. DTD buses only go to resorts so I had the "brilliant" idea to go to POR since it's much closer than Pop. We got off at the first stop and waited a half hour for a MK bus to show. We then had to hit 3 more POR stops before FINALLY heading to MK. The ONE bus stop at Pop was wonderful!
POR is a beautiful resort. It is also absolutely huge and spread out. We had to use strollers to take our kids to the food court, bus stops and main pool. Pop is a fun resort. We had a pop jet fountain and huge Twister games right outside of our building. It is big, but so visually entertaining the kids WANTED to walk and look at everything. The rooms were slightly smaller than POR, but had fewer furnishings and therefore more floor storage space. We loved Pop and will definitely stay there over a moderate while our kids are young! (If I was going without kids I'd prefer POR.)