While the BOSS certainly works as a brake, and as a tuning mechanism, I personally do not like them, and do not own any with them. A few buddies have A-Bolt Medallions in .270 and 30-06. They are very obnoxious, sound-wise. Personally, I don't see the need for a brake on any but the very largest calibers, and even then, I just handload up gradually, and practice getting used to the recoil.
The BOSS is a fine system for those that like it, and it works. It's just plain too loud for me at the range, and in the woods.
KAYR1