The X-Men are a team of elite super-powered mutants gathered by Professor X to protect ordinary humans even as they are persecuted by them. In the wake of the death of one of their own, however, the team has stopped operations for a whole year. Then Professor X receives word of a mutant girl's mysterious disappearance in Japan. Sensing that something larger is afoot, he reassembles the team and sends them to investigate. They uncover a connection between her disappearance and an anti-mutant group known as the U-Men.
So far this is pretty good and entertaining. The action and animation is great. The story is good and fits with the x-men universe. The characters look and behave like they should and the voices fit perfectly. I especially like how it only focuses on the main x-men characters and portrays and develops them all properly, rather than having the humungous, unmanegeable, and underdeveloped cast of the live-action movies.
As a fan of the comics, I can see that it captures the essense of x-men. you feel like you are watching x-men rather than just a japanese interpretation (like the disappointing iron man and wolverine animes).
Not only is it better and more entertaining than the previous two marvel anime, I would say that it is a good action anime in general. Conclusion: High Recommendation!
PS they haven't all shown up yet, but you can tell from the ending credits that they are going to have all the classic villains like magneto, juggernaut, mystique etc. which I believe is a HUGE plus, especially compared to the stupid unknown baldy from the wolverine anime.