I bought two of these mounts for my LWRC M6A2 rifles. The build quality is very good, and it only takes up two slots on a quad rail.
The only thing I didn't like about the mount was the fact you had to remove all the rail covers, flashlights, etc from the rail prior to installing. It is a one piece mount and it requires you to slide the mount from the very front the rail to where you want to mount it. So I had to remove 20 LaRue index clips just to put on the QD mount. Other brands of QD mounts that I have are two piece that don't require anything to be taken off the rail prior to installation.
You can't go wrong with Troy. They make great parts for AR-15s and this QD mount is first class.
Pros: Light weight, Strong, and low profile.
Cons: Requires everything to be removed from rail before installation.
This review was written in the old system and had content requirements that are different than reviews written today.