This graphic novel leads up to the events of Avengers vs X-Men proper. There are stories following the aftermath of the House of M, when the Scarlett Witch decimates mutantkind. There’s also stories related to Hope Summers, and her return to the current era with her father, Cable. Finally, there’s another story that kicks off a series that introduces Magneto as an X-Man.
This is a decent compilation with stories mostly interesting as a transition from House of M to Avengers vs X-Men. If you’re not a continuity junky and are the type to research the interstices of these arcs in some wiki, you can safely skip these stories.
In general, I enjoyed the art in these comics; but the one from the Avengers Sanction series had a style that reminded me of 90s Image-style art, with a rippled muscled Cable and coloring on his arms like a snake.