We've stayed at both and both are great resorts. The WL is great as it's convenient to MK via boat as well as to the CR where you can shop and/or dine there and then hop on the monorail to visit the Poly and GF. The grounds are beautiful, the pool is great, and Roaring Forks is great for quick CS meals/snacks. The lobby is also a great place to sit and take in the beautiful surroundings. WL is a great choice for a deluxe resort as it has all of the amenities of the other deluxes, but is quite a bit cheaper than the monorail and Epcot resorts.
The BC is also a beautiful resort that is conveniently located within walking distance to both Epcot and DHS. The rooms are slightly larger than WL, SAB is fun, and Cape May Cafe is great for both breakfast and dinner. The boardwalk is also close by for nightly entertainment or just walking around.
Good luck deciding, but you really can't go wrong with either one as they are both great places to stay.