I shot a AR with a Battlecomp a while back and was very impressed with how it helped keep the muzzle on target during rapid shots---I was hooked
I've since bought/acquired/home fabricated many different muzzle brakes; some good some not so good. The biggest problem with most muzzle brakes that are effective is noise IMO. Many keep the muzzle on target but at the expense of your teeth rattling. This one doesn't have that issue.
Here's a quick summary of what I've found from the brake I've been shooting for the last few weeks on my 6920:
-The shape of the baffle closest to the muzzle is angled so it directs blast energy to the side and
forward, away from the shooter
-Two top ports direct plenty of energy up to keep the muzzle flat while firing
-No ports on the bottom, unlike some other popular brakes, which keeps dirt/sand from kicking up when firing from the prone
-Made in the USA from US steel
-Phosphate coated, not painted like some others
-No POI shift with the brake vs. the A2
-No machining marks inside or outside that I could see
-It's .5'' longer than the A2 birdcage
-Weighs 5oz. (This could be a pro as well as a con though because the added weight helps keep the muzzle stable)
-I'm not a fan of the breaching teeth in it but I know a lot of people are so it could be a pro as well
-It doesn't come with a crush washer. Not a big deal but just putting it out there so people know when/if they go to order one.
All in all, it's a very effective brake at a cost under $70. I'll be testing a couple more of their lower cost brakes as well over the next few weeks (the TriDelta and the Tactical TriDelta) so I can't say which one is best yet but the Delta ST is certainly an improvement over the standard bird cage in terms of controllability.
Here's a video of me shooting with the A2 and Delta ST using the same gun (6920) and ammo (62gr Silver Bear):Custommuzzlebrakes.com Delta ST Review Video Link
I always test velocity changes with any brake and there was no difference with this model so I didn't include that in the review....
The only place I know of that sells this brake is on the companies web site---www.custommuzzlebrakes.com