First Strike or Escalation? PS3?

I got black ops for free at gamestop. Buy 2 get 1 free. I plan on returning the 2 I bought tomorrow, =)...Anyways..Black Ops being the free one, should I get first strike or escalation? Or none, because I'd be wasting money? Just let me know what your opinion is for both and which is better. I like to play zombies time to time, so yeah. Don't really care about campers, since they're usually dumb enough to stay in the same spot after killing me once. But yeah, opinions and suggestions! Thanks!