My sincere thanks for all the well thought responses. My five year old Sony Grand Wega has a failing optical block, lots of blue showing at right and bottom with all content. Sony is no help even though countless forums are filled with customer complaints on this issue.
Repair could easily run $1100.00, so that's not going to happen and right now I can't reward Sony with another TV purchase. The Grand Wega has always been rolled up against the left wall for music and pulled between the speakers for movies.
Mounting above the fireplace could be a reasonable resolution to all problems and may even help sound since the TV wont be next to my left speaker.
Several of you made points I had concerns for and some I had not even considered. The viewing distance close and far is 12' and 17'. I've looked at several brands at stores, fortunately most were using DTV or Blue Ray so I had good HD quality signal.
So far I'm impressed with Panasonic V10 Plasma 58" and the Samsung LCD Un55B8500 55". Both are excellent but very different as many here have posted.