I went last November, from the 12th through the 19th, and I was disappointed that there were not more Christmas decorations up! Last time I did a November trip around the same time frame everything was decorated.
There were still some up -- Magic Kingdom is all decorated because of the parties, and the big tree at EPCOT was up. The Osborne Lights were going (DO NOT MISS THEM IF YOU GO IN NOVEMBER!).
However, none of the resorts were decorated yet, which was a disappointment to me. Only the gingerbread house at the Grand Floridian was up, but it wasn't officially open yet. The trees at AK and HS were not up yet either, though they were getting ready when we left.
That being said, the crowd levels were great. F&W at EPCOT was over, so those crowds were gone. Universal was practically empty, couldn't believe it, we got off Gringot's and got right back on!
We went in early December in 2013, and I think I did prefer that, but only because all of the decorations were up. The Christmas show at EPCOT had started by then too, which was great. Am debating when to go if I go again this year.