I guess I didnt pay attention when I bought it, but it isnt a traditional "adjustable" gas block, its actually just a two position suppressed/unsuppressed switch. The only thing I dislike is it requires an allen wrench to turn the valve, which thankfully I was able to fit into the magpul grip seeing as how otherwise it cant be adjusted. That being said, it performed well, and properly gassed in suppressed and unsuppressed modes (would not cycle in suppressed mode with no can on, where as many "suppressed" mode settings are still way over gassed), with the suppressed mode being quite a bit softer. I brought two kinds of M80 ball, FGMM 175 and Magtech 168 ammo. It shot the best with the 168s printing some consistent 1-1.5 inch groups (keep in mind im running a Leupold MK6 1-6, so sub MOA precision isnt the easiest at 100 yards with that) and after a couple mags through it, I had a best group of the day with 9 rounds in a 1 inch hole and one flyer 1 inch outside, which I will claim as my fault. Looks like the rifle takes about 150 rounds to break in and it really started making nice groups. With the M80 ball, 2-3 inch groups were coming out of the magtech and consistent 3 out of the surplus stuff. My Scar shoots the same so its definitely the ammo. On the 550 and 750 yard targets, 168s didnt miss a beat and made pinging 12x12 targets a cinch.
All in all, after DD dropping the price of these rifles, its quite a bargain considering the build quality and extras they added in. Its significantly lighter than my LMT, smoother recoil than my Scar 17, above average accuracy for a battle rifle, and maybe if I get some time, I will toss my ATACR 4-16 on there and see how good I can get the groups on it. I bought it as a mid range rifle I could do anything with, and it fits that role very well. Another fun fact is the BDC on the Leupold CMR762 matched up PERFECTLY at 550 and 750 yards using the Magtech 168s. I even let my coworker run it, and him having never shot long range before, I told him hold it between the 5 and 6, then hold just to the left of the target, and while he missed the first round, the 9 rounds after were all hits.
The only thing I wish it had was either a gas block switch for suppressed/unsuppressed, or an infinitely adjustable gas block so I can just dial the gas down to where I want it and deal with a bit more pressure on the suppressed side, knowing that at any time I can grab it and use it, where as now, I have to set it back to unsuppressed every time I finish shooting, as it will not cycle without the can in that mode.