I think it depends on your situation. Are you taking little ones? If so, I think that LT isn't as lively as CM, but then again I haven't been. I have asked many people though, and most say the food is good at both, but CM is a little more "electric". I have a 4yo, so I think CM would be a slam dunk for him, esp since they have the sundae bar.
On the other side, I've also heard some people say that the buffets are a little more hectic. I THINK LT is a familly style thanksgiving meal. If so, that could play into your preference too.