The Wolverine is actually more of a character piece than an X-Men movie. I think there were only 2 mutants in the whole thing. But, I actually liked it more than the last few X-Men movies.
By focusing on Wolverine it gets to actually dive into his character and give him real decisions and growth. It's great to see Hugh Jackman get a full movie playing this character as the main protagonist.
Basically, Wolverine goes to Japan and then things quickly get more interesting. If you like X-Men or Wolverine you should definitely see it.
For me, it's just made me more excited for the Old Man Logan movie they have in development. It could turn out really good.