Crew was pretty good, and a bit reminiscent of Marvel's late lamented Early Voyages comic, available in an excellent omnibus edition from IDW.
Countdown was the lamest load of fanwank I've read in ages. Haven't read any of Nero or Spock: Reflections yet.
Most of the other stuff is somewhere in the middle. I'm rarely blown away by anything IDW publishes, but they're usually not awful, either.