I was pretty against the idea. With that said, recently made the decision to get a 75 or 82 inch and guess what, only place it will work in my room is above the fireplace.... I have found a couple of really nice mounts that pull down and allow the tv to be extended away from the wall, thats what I plan to do. The mount I found lowers the TV 2 feet!
Pretty mad at myself, just built last year, now I have to pull the fireplace and install an outlet and run HDMI etc. There goes a whole day but worth getting it right.