Although I wouldn't NOT stay at the Swan/Dolphin, they would not be a first choice, as I like to carry one piece of plastic (my room card) and a couple dollars, and charge everything to my room. (I find it makes it so easy to keep track of expenses, every few days I get a printout from the desk to look for discrepencies, etc. You can't do that at the S/D. I also don't particularly like the layout of the Dolphin, I find the floorplan very confusing. Another big downer is the lack of balcony's at both resorts. Like I said, if it were either of them or off site, of course I'd choose them.
I've stayed at the BWI, BWV, BC, BCV, and YC. So I think I've got a pretty good set of experiences to draw on. I'm assuming we're ruling out DVC properties, because that's an entirely different ball game.
My favorite would have to by the BC. I love the decor, the proximately to Epcot, the pool, and the lobby. I find the decor in the BWI rooms very "busy". It's a lovely hotel, but I prefer the BC. The YC is a bit to formal and stuffy for me.
The disadvantage to the BC is that some of the rooms don't have a full blacony. But just make a request for a full balcony and you'll probably get one with no problem.
Anne