Not my favorite X-movie but still worth the $9. It was kind of slow going in the beginning but picks up about halfway through. The acting was good - Liev did a great job as Sabretooth. I wish they would have incorporated more of the other X characters but it was nice to see some of the guys you dont hear about in the main three X-movies.
If you're a die-hard book fan - be prepared for differences! The movie is fantastic but strays a lot from the book ... but it has to in order to make sense to people who haven't read the book.
I do recommend reading the book first - some parts will make a lot more sense and will help you understand why some characters act the way they do. It will give a lot more backstory to some interesting situations.
But if you're not into taking the time to read the book(s) just keep an open mind and enjoy it. It's basically Underworld on downers with a lot more romance.
I loved it - just keep an open mind. Did I mention you should keep an open mind?