From the ones I've seen the quality control just wan't very good. Straightness being the culprit. I'm not real picky about straightness but I've seen several dozens where it was just downright terrible. As others have said, they just didn't live up to the hype.

For some reason I still often find myself shooting my ACC's. Can they bend? You bet. Can they break? Again in the affirmative. But that's if you hit something that isn't meant to be shot in the first place. I still have 8 of my original dozen from 10 years ago. Most of those that I've scrapped have been due to shooting tight groups with or without broadheads. Blades can do a number on any arrow shaft.