So I had planned on a Poly/GF stay. Upon arriving to check in at GF, the manager said he had bad news, they "overbooked" my room dur to a wedding BUT he moved us to a 2BR suite at YC.
I had an excellent experience at YC. It was just DH and I, and all the CMs from Bell services to Mousekeeping, to CL lounge were fantastic. My only complaint was the distance from our suite to the 5th floor lounge. But we stayed at an AKL suite on the 2nd floor which was MUCH further away...I was in a wheelchair this trip which made it seem more inconvient IMO.
The resort is beautiful. The walk to Epcot amazing. We watched Illuminations from our balcony. No boat or bus issues AT ALL.
We were in 4209. 2 King bedrooms, living room...LOVELY. And the CMs were able to change ALL my ADRs
The CL lounge is small, and ran out of seating often. But I think the resort...actually Disneyworld as a whole, was busy. The offerings NEVER ran out. And the CMs went above and beyond to make our trip wonderful.
In 2012 we were due to stay at BC, but we changed to Poly, DH wants more time there. I think the MK side is better for us, for now, once the kids are a little older we will try BC.