I voted for the Poly over POFQ. The Poly is so convenient to both the MK and Epcot, the rooms are much larger, you will have 3 sleeping surfaces so that you and DH can have one queen, your DS can have the other queen and your DD can have the Daybed. Very comfortable! In POFQ you would have a much smaller room, no chance of a balcony and only 2 queens for sleeping. Amenities at the POFQ consist of a food court and a pool with a serpent slide better suited to younger children. I believe that your children would prefer the pools at the Poly. For dining at the poly you have Cap'n Cooks for QS, Kona Cafe, O'Hanas, and Trader Sam's at the pool. You can walk from POFQ to POR, but you can walk from the poly to the GF! REALLY NO COMPARISON, IMO.
The Poly has a wonderful atmosphere. It is awesome watching the MK fireworks from the Poly beach or pool. We simply LOVE staying at the Poly.