I've finally gotten around to reading the first story arc (issues 1-4) of Invincible (which is now well over #100). I review it in my latest blog entry.
Kirkman definitely needs to work on his dialogue... at least based on what I read in this first story arc and also the first TPB of Walking Dead (which had even more dialogue problems than Invincible does). But he plots pretty well, and I do like the classical feel of the setting. I will definitely try the next couple of arcs.