For us it's mostly location, location, location. With two special needs children, it's a huge bonus to be able to go back to the room easily if someone has a meltdown. And since we fly, and don't rent a car for the entire stay, Saratoga and AKV are right out.
Loved the BW, but last time I must admit we had a fabulous room right off the lobby, overlooking the pool. Gorgeous!
The fact that the BW and BC have boat access to both HWS and Epcot makes them prime territory for us. (Boats are SO much easier than buses with a stroller). Plus Epcot - and the French pastry shop therein - is a peaceful stroll away.
I'd like to try BLT, because getting to and from the MK from the BW was a bit of a pain for rope drop.
But I hold out faint hope that one day they'll build a resort on the Epcot-TTC monorail line that will have a theme that appeals to me more than BLT.

Yes, I know, good luck with that.
While there are different strokes for different folks, indeed, I think that Disney is learned that their most successful (read here - best selling) resorts either have excellent location/park access OR such profound theming and dining that they are a destination unto themselves. Which is why so many people hate on SSR so much - the theming is nice, but rather bland, and it's way out in the boondocks if you don't have a car. Not to mention sprawling.