I always found that being a fan of both groups, the Legion tended to be easier to jump into because plotlines were not threaded for 6 - 10 years at a time. Granted they had hints dropped early but events like Gambit and Sinister, Days of future past, and the other Summers brother seemed like they went on forever. The worst and longest Legion plotline I think was Shrinking Violet being kidnapped and replaced by Yera.
What does that matter when it takes the same amount of time to enjoy the book? Either I don't know the characters or I don't know the plot-lines?
If I know "who" I'm dealing with I can get somewhere. Not saying I can't learn who the Legionnaires are, but 12 of them?
But all that aside, because it really don't matter in the context of the DC relaunch, reboot or whatever it is they are calling it, because the Legion books that launched at number 1 in the new 52 could only be enjoyed by those who have some knowledge of the characters and not be new readers and that's a huge let down.