I agree, the Copperband has long been my favorite fish...I wasn't suggesting that you would have purchased it strictly as a janitor, but it certainly is a nice added benefit.
I made the mistake many, many years ago of falling in love with the Copperband and buying one before I really knew what I was doing. Needless to say it didn't last. After that, and a few other failures with delicate fish, I stayed away from the tough ones like the Copperband for a long time.
But now that I have a reasonably established and stable reef, with its high water quality and lots of room for a fish like the Copperband to get comfortable, I'm once again tempted.
Unlike you though, if I put one in my tank, it's staying in there no matter what. I don't have a second tank to move it to and can't even imagine how I'd catch it to get it out in the first place!! A 225 gallon reef tank just has too many places for the fish to hide and I'm not willing to rip the whole thing apart just to capture one critter...so I need to be certain I'm prepared to endure the consequences before I take the plunge.