Beach Club without question, especially as you say you want to spend time hanging out and swimming.
First, the main pool at BC is much MUCH better than the pool at POFQ...not just in that it's bigger, but it's more adult themed (the POFQ pool may be undergoing re-theming with the recent refurbishment there...I don't know, but the pool in the past is rather cartoony with the big Mardi Gras animals. Just not my style.).
Second, if the pool at POFQ becomes too rowdy for your mood, you have to walk over to POR for a quiet pool. POR has a themed pool, and that's it. The quiet pool at BC is near the main pool and is fantastic. And both times I stayed at that resort (at one of the busiest times of the year and at one of the slowest), it was *quiet* and very lightly attended with only a few adults on loungers reading books, napping, etc.
Third, beyond the pools, I think the rooms at BC are better than those at POFQ for hanging out. They're a bit roomier and have a nicer decor, IMO. Rooms at BC have a door leading out to an interior hallway rather than an outdoor corridor and have windows looking outside with a balcony (full or Juliet). Some rooms offer a full sized balcony, if you'd enjoy hanging outside of your room with a glass of wine or coffee. Even those with Juliet balcony's allow you a bit of private outdoor space if you like that (my sister and I had connecting rooms...we each would open the door to our little balcony at sunset and lean out to people watch as we drank our afternoon wine).
Finally, while POFQ has the boat to DS, BC is right next to the Boardwalk area for dining and entertainment. AND, if you enjoy fireworks, you can sit near the beach, by the pool, or in your room depending on the location and see some of the amazing fireworks from Epcot.
I haven't stayed at POFQ yet but LOVE POR, but I'd stay at BC for a few days relaxing over any mod easily...it's really a no brainer for me.