Astonishing X-Men Omnibus
Great story for fans of the X-Men, and very "Joss Whedon". I loved that the first few pages gave a history of the main points in the X-Men timeline so far, even though there were still a lot of things that came up in the story that suggested previous knowledge was needed to fully understand what was going on (who the hell is Agent Brand?!?).
And I think this is why I tend to steer away from the main Marvel and DC universe comics: there is just too much to keep track of, stuff that could have happened dozens of issues ago in a completely different series. I know some people love all the intertwining stories in these comics, but sometimes it can be a bit too much for me.
That said, taken on it's own I liked this book. This isn't the X-Men that I grew up loving as Kurt and Ororo are missing, but I liked the dynamic of the new team. I did have a few qualms with the story as a few elements seemed to dissappear without warning, but I probably should have expected that to happen being part of a continuing series.