I believe it is the VESA mount, the UE55TU8507UXXU VESA mount is 400 x 300 whilst the UE55TU8500UXXU is 200 x 200, this is only an issue if you are going to wall mount, otherwise, they are both identical.
WHY RELEASE 2 IDENTICAL TVS WITH DIFFERENT NAMES IF THE ONLY DIFFERENCE IS THE STAND????? I've just spent an hour searching through the specs trying to figure out which is the better TV and they're exactly the same...! No explanation, just 2 different TVs... infuriating!
I've seen this in the specs, when you say "this is only an issue..." what exactly is the issue? as in, is there a negative with one of those VESA configurations?
