got a 15" 7-08 that i wouldn't want a brake on. recoil is very tolerable. but....people are different, and if you are recoil sensitive, or want to shoot with it all day, or in competition, then maybe a brake would help ya.
a brake will add much more noise, and be louder.
havn't tried magna-port.
OTT(on target technologies) makes a screw on muzzle brake. you could even take it off and use a cap to cover the threads. i have the OTT "shark gill" brake on my 300 win mag encore handgun. very nice!