I think this movie kicked ass. It was dumb, but it was a fun, tight kind of dumb. Ritchie's trademark nonlinear editing shaved so much exposition and bloat from what could have been a 3 hour fantasy movie. The CGI was... well, there was a lot, and it was ridiculous, but it embraced ridiculous. It was a cartoon at points. I LOVED (loved loved loved) the soundtrack.
I think really the only real issue I had was the mage's acting, but that really only stuck out badly in her one longer monologue.
It wasn't high art by any means, but fuck I had fun. Can't say I've ever seen a movie with a giant snake fucking up a castle while a blues solo plays before.