Chobits Manga

[Phantomizer]

Hey everyone, hoping someone can help me out here.

I'm planning to buy the Chobits manga, i'm looking to buy it new, but i might have to settle for used because i want the individual volumes for collection purposes, not the omnibus versions. But anyways, my question is the following: On this particular manga, is there any noticable difference between the regular volumes and the omnibus versions? I was told that sometimes there are differences, like one being printed on better quality paper, having a few pages in color and so on.

So just wondering before i commit to anything :)