That's a tough choice as we've stayed at both. I chose BCV, though, because of SAB. We also like having Beaches and Cream so close, plus the extreme proximity of the World Showcase. The benefit of staying at BCV is you are also very close to the fun at BWV. Boardwalk Bakery, ESPN, Surrey Bikes, Boardwalk Entertainment, etc. Those are my favorite aspects of BWV.
BUT, if I were going with someone older or who had more mobility problems, I'd pick BWV. The 'action' is closer and more easily accessible.
It's a hard choice!!!