I would say BC or BW (even though it's not on our list

)
We stayed in BW studios, and Poly studios last summer, and while both were incredible I would prefer BWI. The Poly had better pools and nicer rooms, but the location of the BW is just amazing.
The Beach Club is awesome, but the pool gets crowded from what I hear. Having said that, the main pool at the BWI is pretty low in our rankings as far as pools go. We just didn't like the aesthetics that much. We should have tried one of the quiet pools instead.
We are at the Poly 8 nights this summer, and if I had my way I would have done another split stay but the BW was all booked up (I looked too late)
Dan