A:Answer I have a 65" Samsung (width 56.9") which can rotate to about 45 degrees on the "Sanus Premium Series Swivel TV Mount for Most 42" - 90" TVs" ($319.99 at BB). One edge of the TV is very close to the wall, while the other edge hangs way, way out into the room when turned to the max, but in a corner-mount situation it would make sense. An LG 77" CX (width 67.8") TV will presumably turn a little less than my 65" due to the extra 10.9" of width (5.45" on each side of the pivot point) hitting the wall sooner, but still pretty far - my guess, around 40 degrees.
Be aware that the cable management of the mount runs cables thru the extension arms, which took up about 4 feet of cable in my setup before even starting to head off to other equipment, so plan for that. I got 12' HDMI cables, and I kind of wish I'd gotten 15 footers.
