Omnibus edition? As far as I know, the KotOR comics don't have Omnibus editions, just Volumes (6 being released so far).
On the comics itself: I like it. I love the characters, and it's an Era I'm very much interested in. I think a few problems people, me included, have with the series is that the quality of the art is inconsistent (they've used tons of artist, and not all of it was very good, in my opinion), that the story loses its focus for a time, getting sidetracked by other plots, and that characters created in the KotOR games (some get an appearance, you'll see), get fleshed out in a way not everyone is satisfied with. The latter is to be expected, I think. People made connections to these characters, filled in the blanks with their imagination, and get to scrap that when the writer decides something different happened, something less enthralling than they had in mind. Anyway, I think they could at least improve the art. Sticking to one, preferably those from the first couple of arcs, would be better.
Overall, I really enjoy the comics, though. I manage to ignore the little things that annoy me, and really enjoy everything else. I'm not exactly a comic reader myself (Next to this, I've only read the Legacy comics and Tales of the Jedi), so perhaps I don't expect much.