I bought this issue because it's the first issue of this series' crossover with Guardians of the Galaxy. I'm not that familiar with this series, but I was able to figure out the gist of things. This is the original X-Men brought forward in time from a point where they have recently begun as super heroes
As for this issue, I enjoyed it, but I don't think I really needed to buy it to understand the story being told in crossover. It's pretty much mostly set-up, good set -up, but set-up nervertheless. The X-Men talk to introduce new reader like me who have just tuned in for the crossover, the Shi'ar attack and kidnap Jean Grey and then the GotG show up a bit too late. I'd say it makes for a good, but not great, beginning to things.
Thank you Troy for the sig