It's fantastic, if it wasn't for that product, our TV would not be over our mantel. Years ago when we went from our stand + TV (early, Sony bulky LCD), to a Plasma, we had it setup for a few months, but in a room that's:
Wall 1 Window
Wall 2 Fireplace
Wall 3 Solid
Wall 4 open ...
If you use a stand, there's only two places (Wall 1 and 3), and you need some wall space for seating, blocking the window is so-so.
I stumbled onto the MM (Mantel Mount) from the AVS forum, very early in the company's inception, when they were "working out of a garage", everything was scratch hand built, there were not model numbers because there was only one product, and it was ~$200. Since then they've added higher volume production, more than doubled the price, created a few tiers of products, some new options, even a fully automated version.
Anyway, it's been up since Dec 2013, on the 3rd TV to use it, with zero issues, always works as designed, allows for adjusting the counter balance, easily handled different weights, sizes, VESA specs.
Covers are available to cover the mounting bracket, and/or you can put it at about 80% down and the mechanism isn't visible.