My phillips buzzes a little but you have to be behind it to hear it.
I have a 50 inch and it puts out a good amount of heat. Can't imagine how much heat a 63 inch puts out!
I have a 50 inch Pioneer Plasma (top of the line in Plasma TVs) and a 42 inch Panasonic Plasma TV. Once you go Plasma, you never go back. :) And I don't have any heat or buzzing issues people are talking about. Of course my Plasmas are on TV stands and not on the wall, so they might have a little better air circulation.