The AUG handles like a refrigerator compared to the AR. The trigger sucks. Magazine changes are S L O W. If you drop the mag (or tap the bottom of the mag too hard while seating it) the rounds pop out. If that happens while inserting the mag, you now have a type 2 0r 3 malfunction. Oh, did I mention that the trigger sucks, too? Also, unless you have a left-hand bolt (and some extra time to swap parts in the middle of a firefight), you're gonna have to shoot that (bull)puppy right-handed - and don't even think about transitioning to left shoulder/hand for engagement around a L/H barricade/corner. You'll have to lean out and give Tango more to shoot at.
The mfgr. made a big deal about being able to drive a deuce and a half over the gun repeatedly with no ill effects. The Aussie troops, initially disappointed, were not deterred. They next drove Centurion tanks over them so that they would be crushed and could then get ARs...