Well, I've only had mine for a couple weeks, but she's definitely one of my favs. I have her stocked with all the fish in my signature below and she gets along well with everyone. The Kole was a bit aggressive at the start, but now they actually seem to prefer being around each other. They're usually found in the same area of the tank.
She is a very peaceful fish - hasn't picked on any other fish or any of my corals (soft, lps, and sps). She just slowly moseys around the tank, picking at occasional algae (including hair algae!) and LOVES nori - makes quite a mess of it really. She'll eat meaty foods happily, too.
These are known to be hardy fish, but know that they can change color VERY drastically. She can quickly change from brilliant yellow to an alarming splotchy black/grey/white. Might make you think the fish is sick, but it's really just stressed (easily done) or in its night colors.
Hope this helps!