I have three 6.5mm CMs and none of them have muzzle brakes and really don't need them. I don't notice any particular issue with keeping on target after recoil with any of them.

To give you a working comparison, I have two .308s one with and one without a muzzle brake.
From a bench, I don't see any difference in the effect of recoil between the two, especially if I have my set up right when I squeeze their triggers.
All the muzzle brake seems to do for me is to rile up the shooters at adjacent benches.