Survival offers very good DPS along with replenishment. Not so sure how it works out for a multiboxer. I am running a paladin/shaman/3xhunter team at the moment (level 78). One hunter is MM for the group AP buff, two are survival. I know that 3x explosive shot is pretty nasty, but on outdoors mobs the MM hunter stays ahead in total DPS because even without a sting active, Chimera Shot is critting for around 4500, while the mob dies before Explosive Shot can run its course. I've yet to test on elites or bosses (or even target dummies), but will probably try that soon.

I just don't know if you can keep up an optimal rotation with survival in a mixed group, since some of the procs (lock and load, for instance) can require a specific shot selection to improve DPS. MM might be better as part of a rotation that can be spammed and not micro-managed.