I'm afraid I must be on the dumb side of this one. I seem to recall there being some question in some studies regarding whether high aggression levels in users of anabolic steroids were "side effects" or "concurrent behaviors", but aside from that I'm drawing a blank on references to the terms in relation to each other.

I did find the reference humorous, though, if only because of the way it hearkens back to Microsoft's bug/feature repackaging effort. Is that perhaps what you meant?

I'm still of the opinion that the best license plate ever was one that said "feature" and was located on the back of a VW Bug, by the way.