I have one on a franken-build I did. Lightweight ambi forged lower and upper, 16" pencil barrel, piston driven setup. Used a Fortis Rev II forearm so i needed a rail piece up front for the light head. Bought an expensive one from company in Cali with Japanese name, can't remember.
My only real issue with the system is the grip. It is longer than a normal AR grip, too much hanging out below my hand when running it. Mine was uber eager right out of the box, the wireless button would activate the light/laser no matter what position the master power switch was in! I found that annoying and sent it back. I have it on my coyote gun and really like it come last 15 minutes of the day and walking back to the truck.