axxo is a one (maybe 2) men release group who has contacts with the scene, takes their rips, re encodes them to fit in a 700mb CD, and doesn't thank the Scene release group for them...
he publishes all his stuff on public trackers which is why he's famous.
he does post on DarkSide_RG, but is not part of the uploaders team.
he apparenlty uses one of his friend's app to encode his rips and usually doesn't do a great job at it.
if you want to know whether the private tracker you're using is bad, read the rules and if they accept aXXo Rips, it's bad!