When we stay at BC (or YC though we prefer BC), I think that it's my favourite resort. Until I stay at BWI, and then I think that's my favourite resort. They both have their pros and cons, but since they're in the same area and have proximity to all of the same restaurants and lounges, the differences are minimal IMO. Stormalong Bay is awesome, but we also love the quiet pool at BWI in the rose garden. We hop back and forth between the hot tub and the pool and we may be the only ones there for hours. The main pool is still quite nice, and we do like the pool bar for snacks and drinks. I think the rooms in YC are larger than BC which are larger than BWI though it depends on the specific room/location. Storage is, I think, better at YC/BC but it's not horrible at BWI.
While you can be far from the lobby at BC, you may be located near to an exit door that opens out to the pathway closer to Epcot than the lobby doors. YC exits closer to Swolphin if you want to eat there and is closer to the boats and closer to Hollywood Studios if you're walking. BWI is a little farther from Epcot than BC but closer than YC.
It's really hard to choose so we often end up choosing based on cost or availability or staying at a different one than last time or where we expect to spend most of our time. In September, we're staying at BWV because it was the same cost as a room at BWI and we are only there for two days visiting Epcot and Hollywood Studios. BWV is a little farther from Epcot than BWI but closer to the pathway to Hollywood Studios; essentially halfway between both so we choose to stay at BWV which we wouldn't normally do. IIRC there was no availability at YC or BC or at least not for the price we wanted. Or maybe I just wanted to stay at BW - I don't really remember now.
I will say that we stayed at BC over the Christmas holidays a few years ago and the pool wasn't too crazy all day long; there were definitely times it was good and I remember spending a fair bit of time on the lazy river. The next year we were at BWI though earlier in December - not over the holidays - and we spent time in both pools (quiet and main) and it wasn't too bad though it might get busier closer to Christmas. I really don't think you can go wrong with any of the three. Lots of people will be at the parks during the day so you may not find any of the resorts particularly overcrowded or at least not all day.