Muzzle brakes have an advantage in second shot follow up by reducing muzzle climb and recoil impulse, both very desirable in shooting, however one has to weigh them in relation to other requirements. If you're civvy street or making stoopid (with two "O"s) long range shots from optimal conditions and positions there is no real draw back. When you start talking about stacking up or firing from a concealed/enclosed position (sniping, FIBUA/MOUT, CQB) or firing in conditions of reduced/altered light, a muzzle brake is a very bad thing. The noise, excess gas and burnt/un-burnt powder all lead to increased audio and visual signature which can jeopardize those involved through compromising their visual, audio and tactile senses.
There are several good flash suppressor/muzzle brake offering on the market that while they don't do both as well as the specialized kit, provide a more than acceptable result
If this is true, then why do nearly all Accuracy International offerings have them? Argueably the best sniper weapons in the world, used by more elite forces than we could likely all name if we tried...
not trolling - actually want an honest answer to this.