We like both BC and BWI, but BC is a clear favorite for me. Our children are ages 5, 12 and 13 and they all love BC. But we're staying at BWI again later this month for two reasons: 1) we stay at BC a ton and my husband wanted to mix it up; and 2) CL at BWI is really amazing - wonderful CMs.
I prefer the room decor at BC, the general theme, the lobby, the general layout of the resort, BC Marketplace for snacks and drinks, Hurricane Hanna's for poolside snacks and drinks and the wonderful music they play around the grounds. It's so easy to refill mugs at the self-serve station (no self-serve at BWI) and nice to have the Marketplace so easily available without going outside. And the pool at BC is just so much better for our family. Can't say enough about how much we all love SAB!
There are things I love at BWI, but most of that is related to BWI CL. I don't think we'd choose BWI without CL because there is no BC Marketplace or Captain Cook-type location for quick snacks and mug refills at BWI. Yes, there are many places to grab snacks and drinks on the Boardwalk, but with three kids and different tastes, it's easier to have lots of options all in one place without having to go outside, wait in separate lines or pay at separate registers. As a result and because the CL CMs at BWI are so welcoming, CL becomes even more valuable to us at BWI. The other thing I love about BWI CL is that, if you book a standard CL room, you will have either a garden or boardwalk view. Can't really go wrong there, because garden is likely to have some view of Epcot and the high Illuminations fireworks, and the boardwalk view is a beautiful water view with BC/YC across the lake and the MK fireworks in the distance. I just think it's incredible that we can book and pay for "standard" view at BWI CL and be so close to the lake.
But if booking non-CL, my BC vote is even stronger!