It IS a fairly efficient brake for recoil reduction but is abusive as hell to the shooter and those around. Having shot many rifles with these brakes everytime a shot is taken there is a significant blast taken to the face of the shooter. Much like being slammed in the face with a garbage bag full of popcorn. The amount of debris raised from the ground if shooting the rifle prone is impressive and unnecessary.
For this reason we have developed a replacement brake that eliminates the slam to the face and raises about 75% less debris .
I fully agree with Rick's assessment of the Steyr brake. I had an HS.50 and while the brake does a good job at mitigating recoil as well as putting on a hell of a show for onlookers, it beats the shooter up with significant muzzle blast being directed rearward.
My LRT-3 with the new brake that PGW has been furnishing these rifles with is a pleasure to shoot in comparison to the Steyr. If I kept the Steyr I probably would have bought an ATRS brake for it.