Here is my two cents. I have researched brakes quite a bit for my 300 RUM. I have shot the 300 RUM with a VAIS Brake and without. The VAIS brake on my buddy's 300 RUM actually produces the same noise that my Savage in 270 win mag produces. It also produces less recoil than the 300 RUM with the VAIS brake. The VAIS Brake is the only one that I have found that vents down range. However, It doesn't give as much relief as some of the other Brakes do.
The other option I was strongly considering is the Defensive Edge. The Defensive Edge reduces more recoil according to most users than the VAIS Brake, but I can not comment on the noise levels, as I haven't shot with it yet. I was going to have a Defensive Edge put on last summer, but decided to wait. I wanted to shoot heavier bullets, but decided to stick with the 168 grain for the time being.
The Defensive Edge is supposed to allow you to shoot in the prone position without kicking all the Dirt from beneath you as it only vents to the sides. The VAIS brake vents both down range and has vents all the way around like a tradtional brake.
These are the two front runners I was leaning towards - I was actually gravitating toward the Defensive Edge, because they are just 30 minutes drive from me and I do not have a relationship with another gunsmith that I would feel comfortable asking to install a VAIS brake, so I would end up sending my gun to Texas if I chose the VAIS route. The cost are very similar from one against the other.
www.muzzlebrakes.comunder the frequently asked questions there is a link to a test that an individual did with decibel meter with the VAIS brakes on his personal guns vs. guns without.
http://www.defensiveedge.net/products/products.htm
