We have stayed at POR and POFQ. We prefer POFQ because it is a smaller and more compact than Riverside. We also like the theme a bit better - my DH is an avid jazz fan. At FQ all rooms are convenient and there is only one bus stop. You share a bus with Riverside and often you are the first stop at FQ giving you a better shot at seats ... and the first off at night. That may have changed but it was that way two years ago, before they closed it.
Riverside is also very nice. Rooms are the same size. The decor inside the rooms and on the grounds is what is different. Keep in mind that POP is newer so everything will seem very clean. FQ was just recently completely refurbished and Riverside is in the process of being.
We much prefer the food court and the general atmosphere at Riverside and FQ than when we visited All Stars. Haven't been to POP so can't comment. For us, the moderates are the best choice. I think it may depend on what you are used to ... and what theme you like.