I just started Bulletstorm tonight! I played the prologue and first two chapters. It's definitely fun and it's definitely over the top, but from the reviews I was expecting a lot more dick jokes. Maybe that comes later. The sets are beautiful and there's some really cool set-pieces. My only problem is that it's impossible to tell your buddies apart from the bad guys; I recall I had that same problem with Gears of War.
It's hard to kill the bad guys in different ways to get more points, though. And it's really hard to get a head shot even if you whip him and he freezes in mid air briefly.