I gave my two cents and much more in my official review:
HERE as well as in a blog entry HERE.

But for the record here, I thought it was absolutely worth seeing, but that it concentrated a lot on action sequences, while leaving a lot of characters with nothing to do. It’s a WAR! Time to bust out the mutant reinforcements. But nope, doesn’t happen. Still, lots of good stuff in this film—nice set ups for X4.

And that post-credits scene: very important. It sucks that so many people didn’t know about it.