I just listened to the now famous Rahm Emanuel on Face the Nation. From what people have said about him, I expected a tiger! After all, Josh Lyman on the West Wing was supposedly based on this guy. But I didn't find him all that impressive. He sounded like a regular person, only with talking points.
But not everyone can be like Newt Gingrich on Meet the Press--right after the Republican victory in 1994. Newt told it like it was, and he didn't give a rip what anyone thought!
But the soft-spoken types can be effective, too. I'm not sure how much they shake things up, but they can probably wheel-and-deal like the best of them.