Imho BM is not that good at 29.
MM if you wanna dps, Surv if you wanna help support - i.e. help stop flag runners in wsg, help protect your side's flag runner w/ better traps, etc.
Some do 5/5 in the BM talent for more hit points, then survival for traps and even more HPs.
MM is the simplest and probably the most common.