Sorry I didn't see this sooner. I have a Noveske 11.5" and love it! Its accurate as hell. I have shot 62 & 55gr ammo through it and have not seen any difference in accuracy. You cant go wrong with a Noveske. I've never even heard of Black Hole barrels. As far as the pinned gas block, I sent the...
Buy Larue, and avoid Botach like the plague. Seriously its worth spending the few extra bucks to get your item without any BS. Here is a link to the Larue website where you can get the TA33G-H and mount combo for $980.
http://stores.homestead.com/Laruetactical/Detail.bok?no=354
Brakes help cut down on baffle erosion. As you can see in this pic the brake has taken a heavy beating. Its worse with SBR's because most of the powder doesnt burn off fast enough before it leaves the barrel.