If there was a 6-10 part main story with some assorted tie-ins then it might be different. I don't read most tie ins for most events either. I am not reading Excalibur, Marauders, X-Factor, New Mutants or Wolverine so I am not getting the complete feeling of it being moving slowly. Even Cable and Hellions I did not read as part of the story either so all I have read is X-Men and the X of Swords one shots as actually part of the event. The flip flop Marvel did on everything being required reading almost made me skip it altogether.
However, if I was reading every single book as if it was a 22 part story I might start to look at it as moving very slowly.