Good point on the angle of the Center. I am still concerned over the height relative to the L/R's, but the venting of the fireplace eliminates the possibility of anything other than the flat screen being directly above the fireplace. Since the tray in my ceiling is about 3', that would put the center 3' in front of the TV if I located it there.
Not to worry about the height front back issue, the avr compensates for the timing etc, it sounds quite natural, at least I never noticed much of an issue with my old set up; the M80s were about 2 ft in front of the center.
