It must just be me but I can't recall ever running into boosters in BO II, granted I play KC basically exclusivly so it probably isn't the mode for them anyway.
I've run into several boosters in hardcore Kill Confirmed. The worst was on Mirage about a week ago. I never could find where they were boosting. One guy on the other team called in three VSATs, EMPs and Warthogs. The last place person on my team was on his friends list.
Boosters have been pretty regular since the map pack dropped though oddly it doesn't seem that people are boosting the Peacekeeper.
I have seen them a lot in KC the past week and I have only played it casually. For there to be at least one set in roughly every other game that is a lot to me. --- "Cover your receptors Perceptor." Driver picks the music. Shotgun shuts his cakehole.