You have no idea.  Seeing it with a packed audience reminded me of Kick-Ass, that sense that there was this awesome, gutsy movie that actually existed and we were seeing it.  And the fact that it's the same pairing of talent is a big reason for that, I think: I'm not nuts about all the details in all his books, but Mark Millar has a real talent for taking a mainstream idea and pushing it into an interesting and extreme area, and Matthew Vaughn is able to not just express it incredibly well visually, but to do so with dry humour and a style that takes some of the edge of.  Any other director and this movie would be brutal and cold, but it doesn't.