The AK74 style muzzle brake, while effective, is one of the loudest muzzle brakes I have ever used.
Very effective, the simple design fights muzzle rise which helps to keep you on target during rapid fire. The downside to that is that all the muzzle blast is directed back toward the shooter. I have fired a lot of things with muzzle brakes including a single shot 50BMG and it was not as bad. You can feel the concussion in your chest.
Overall, an effective design but is rough on the shooter.