I have one that I tried out on a match upper...
It is certainly high quality, but it is a wide piece o' wood...er, aluminum...and was just too wide for my hand (and I have a pretty good size hand). I never felt truly comfortable with it and went back to an Armalite round tube.
It uses a pretty slick mounting system...
There is a big aluminum "block" that screws onto the upper receiver as far as it can go and still line up with the gas tube hole. Then you poke the barrel in and secure it with a simple steel "collar" that screws into the barrel hole in the "block". The "collar" has two holes in it and I used a CAR stock spanner to tighten it down.
After the barrel is installed, you just slide the back-end of the forend...yes, I meant to say that...onto the "block", secure it with 4 button-head socket screws, reinstall the gas block and tube and away you go.
I actually had to do a little custom fitting of the front of mine to let the gas block seat properly and it is very easy to whittle on. I ended up using some kind of bake-on heat resistant paint to get a good final finish on it.
I will tell you, it was very sturdy, it never moved one degree, and it was GREAT over bags or on a tripod. Plus, you don't see them often so it is still kinda' "trick", AND it is more than sturdy enough to screw mounts into for whatever you want to hang off it.
Although it is aluminum...it does give a muzzle heavy feel.