The one thing that drove me nuts about the GF was the crowds. Because the resort is so beautiful during Christmas, and justly so, it attracts a lot of people and the lobby can get extremely crowded (and can be, at times, not that relaxing). It should also be noted that you may not walk through the lobby every time to get to your room unless your staying in the main bldg concierge. It didn't necessarily take away from the Christmas theme, but it certainly wasn't the same as passing through the lobby of the BC or BW every time we went to/from our rooms. I should also mention that lots of people resort hop to check out the decorations so it's not just the GF that's packed with people; however, it was just more noticeable at the GF. Especially the area by the entrance to the monorail on the second (? I can't remember) floor.
Whatever you decide, Disney is truly magical at this time. Enjoy all the resorts- definitely resort hop if you get the chance.