Normally I would say go with BWPPI but if swimming is really important then I would say Carousel. I only say that because the BWPPI's pool is tiny and from our experience, totally overcrowded - so much so that we've always been unable to use it.
We had a bad experience at the Carousel over Christmas and will not stay there again. I sent a complaint to management and they said they were refunding me for one night...which I never received.
We always stay at the BWPPI, but swimming isn't high on our priority list. I have noticed that the pool is pretty small but it's never appeared overly crowded on any of our stays.
We preferred the pool at the Carousel. Both properties were about equal otherwise, but the Carousel prices have been consistently higher the last few times I've looked which has steered us elsewhere. For the same price, I'd definitely go Carousel.