Having stayed at all three (BC, WL, and AKL), I have to say that it depends. In my experience, BC rooms are larger and the beds are more comfy. There is also a graciousness to the lobby. Here's an example: walking in from the rain at BC, we found baskets of towels in the entry way for us to use on our wet selves. Lovely. There are real towels in the restrooms off the lobby. I think YC has cold water available with little plastic cups in their lobby. Not sure about BC. These little touches remind me of other really nice hotels like Grove Park Inn in Asheville, NC.
By contrast, AKL and WL are all about the theme. The rooms are fine just slightly smaller than BC. BUT, they have bunk beds, which our DDs really like. The lobbies are magnificent. The WL has the boat to MK and the lakefront location. AKL transports you to Africa. An experience in itself. And, the dining at AKL is, IMHO, the best on property besides maybe GF.
I don't know if I've helped you at all. These are my three fave resorts. We've stayed at WL twice, AKL twice and are coming to BC for the second time in late Sept., having originally booked WL. The pool debacle changed our plans for us. I would stay at any of them again in a heartbeat. If you love EPCOT, BC can't be beaten.
No matter which you choose, I think you'd be happy. But, yes, there is a difference. Whether it's worth it or not is a personal choice.