Not sure about that. I used it on my old website, then I became a premium subscriber on Labrocca's website and downloaded something different.
Navigate over to a members profile (e.g. my profile), it displays a box with all my additional usergroups:
I personally believe having your additional usergroups displayed on your profile page rather than postbit looks a lot cleaner.
Say for instance you have five badges, and four of those are additional usergroups, it would only cause dilemmas on the forums if all of them were displayed at once.