The LN52A550 is now using the WMN5090AN Auto Wall Mount. Very nice! With the three preset positions, you really don't have to do anything else to it after the initial setup...ok, if you have a batch of kids sitting on the floor...or whatever...you might want to angle the set downwards for them. We don't have any glare issues to adjust for as the 550 doesn't have the glossy screen—which is the main reason we bought it rather than one of the "upgraded" lines.
FYI, the installation is not a one person job. The TV weighs 60 lbs without the base and the mount is substantial. Operation is smooth and quiet. When you power the TV down, the mount retracts automatically. On powering up, it returns to its last position. Really, very nice.