Dark Heresy is most excellent!
I'm a huge fan of in-person, tabletop die-rolling, role playing gaming!
Getting the interaction in person, seeing people reactions to stuff you/ your character says/ does. Having to improvise, on the fly. Especially with some of the down and dirty stuff an inquisitorial team has to deal with.
Imagine this...yeah, you're an inquisitorial acolyte...you're also just one guy, all alone with a couple other acolytes. Throw too much weight around, and you can vanish pretty easily. Some folks in game might find it easier to simply flush out out an airlock than deal with the heat of an inquisitor.