This may not be the cheapest but you get what you pay for On my 11.5" mid-length barrel, the adjustment nut is flush with the front of my 10.5" rail, so access for adjustment is easy. I used SLR's .625 dimpling jig to dimple my barrel. White the set screws seemed solid enough, I wanted to pin the gas block for added security. On the right side of the gas block is a flat and a starter hole to make this painless. I used a 1/8" cobalt bit and a drill press to cleanly get through the QPQ finish. I'm amazed that this weighs less than my front BUIS.
Runs flawlessly at gas block setting 7 from closed. My setup for reference: 11.5" mid-length barrel, surefire Socom 556 muzzle brake, Fail-Zero M16 bcg, standard spring, and 3oz CAR buffer.