The view!
When I stayed at the CR, we reserved a wing room but were upgraded to a Tower. It was great! I loved the view, and we weren't even on the best side. Also, I must say, it was a real treat to only have to walk a couple dozen steps to get from my room to the Magic Kingdom. This is an especially nice if you have young kids or sore feet. Surprisingly, the rooms were pretty quiet. To me, the great advantage of the CR is being at the resort that the monorail goes through. I would think that staying in one of the wings is like staying at the resort next to the resort that the monorail goes through.
Of course, the wings give you a more affordable way to be close to MK and some prefer them for being a bit more quiet. Hopefully, someone who has experienced them will provide their input.