Both resorts are great!
But BCV is my fav!

due to the proximity to Epcot, MGM and the Boardwalk! It's a beautiful walk to all of these!
Everything is there!
There is a lovely Beach Area and it's huge! The last time we were there, there was a party being held on the Beach!
The quiet pool is great! Can't comment on SAB, since have yet to have the pleasure but from what I hear, the best pool on property!
They have bus service to MK and AK too! If you are not up to walking, you can take the boat to either MGM or Epcot!
It's fun walking along the Boardwalk at night too!
To make up your mind, I would chose depending on when you are planning on going to WDW. If you are going during F&W or Flower Festival definately choose BCV! For Christmas, it's a toss up. But my vote would be BCV since you can go and Visit VWL anyways.
Good Luck with your choice, but really you can't go wrong with either resort!
j