From your choices, I've stayed at 2 of the resorts: WL and BC.
WL pros: boat transportation to MK, beautiful lobby area, gorgeous pool, room rates are lower than other deluxe resorts, great restaurants, lovely landscaping. It is a very warm, inviting, and relaxing resort.
WL cons: (and this could be a pro depending on how your perspective) WL is more secluded than the other resorts on your list, small dark rooms, you have to take the bus to parks other than MK.
BC pros: FANTASTIC location-steps away from the WS entrance to Epcot and all of the entertainment on the Boardwalk, best pool on property, boat transportation to DHS, and great TS restaurants surround you.
BC cons: Rooms aren't very big (compared to Contemporary and Poly) and do not allow for much privacy getting ready in the mornings (the bathroom set up in the Contemporary and in the Poly is much better,) the hallways are REALLY long and it could be a real hike to get to the lobby area from your room, CS locations are lacking.
My family isn't planning to return to the BC because the rooms are quite uncomfortable for us now that our boys are getting older. It would be much too expensive for us to get 2 rooms there.