I think the biggest difference is the theme - POR is more lush with landscape, very green and homey. CSR is more what we call SW Tropical, more SW type landscape and decor. Also convention vs not.........that makes a big difference to some people. But if you ask me, the conventioners are working and that leaves more pool/bus space etc for me !
POR - we have stayed AB and Mansions. Mansions has very pretty rooms and buildings and pretty gardens. We did not care for the "boring" quiet pools, felt like we were in an upscale apt complex. AB rooms are very casual and rustic (plus is trundles for some), landscaping is lush and makes for lots of privacy. Loved the free form private quiet pools. Old Man Island which houses the main pool in an island in the middle of the resort so to walk there from anywhere was not bad. Good food court, has atmosphere, options and lots of seating. Pool is nice, L shape, each end geared more for adult or kids. Slide is fun for younger kids. Playground is average. Water amenities and boat to DTD is a real plus. Some don't like transportation, but that will be relative to time of day you are riding. Great atmosphere of southern charm.
CSR - The newest, and I think they always try to improve each time. Would call it more of a deluxe-moderate due to extra amenities. Downside to some is the convention center, but if you don't hang out by the front too much, we weren't really aware of it. "Food Court" is high end where you get some service and they add a tip. We have asked the tip be removed when we were not served by anyone. Pool amenity is the best. Huge pool, lots of seating, some covered, great playground, great slide for all ages, huge hot tub, food/bar right there is a plus and the setup is great that you don't need to walk to main building while at the pool. But the down to some is they think the walk around the lake is too long. We didn't. Actually a plus for DS who is a runner. Stunning resort at night. Water amenities and good transportation. Quiet pools were very peaceful. We would not return to Casita section (too close to convention/main area) but loved Rancho and Cabana.
POFQ - haven't stayed, only ate and walked. It has it's own very strong following of guests. Never really appealed to us personally, too quiet and empty looking. Always thought it would be great for adults only or those with small children and needing quiet time.
I think it depends on the style you want and how much you will be using the pool and other amenities for each particular trip.
Either way we would stay in POR or CSR in a heartbeat !
