i've had mine for about a month now and "so far" things have been great . he doesn't bother my other fish or my corals , and just seemes to be very content swimming in and out of my live rock . He does like nipping at the live rock though but i think its just him looking for something tasty.
Your never out of the woods. It can be a model citizen for years then turn on you. In a softy dominate type tank your pretty safe. Can take a liking to some LPS and SPS over time.
Just be prepared and have a plan in place to get the fish out if it does turn. There are some threads on some pretty good fish traps out there. Mine works great and can catch any fish that isn't so sick that it stopped eating.....
Don't ever let your guard down. I have had one in my tank for about 5 months and everything was fine. 3 days ago I added some new corals and changed some of my rock work around. I don't know why, but the coral beauty apparently didn't like the changes I made and turned into a real thorn in my side. It has taken to nipping at all of my corals. It tore apart a rainbow acan lord I have. So I would keep an eye on it anytime you add stuff or make changes. In 1 day this fish may have cost me a $200 piece of coral. Hopefully I can save the polyps that have not been torn.
I had a flame angle that was good for almost 3 years one day he became a connoisseur of sps destroyed my tank had to tear it down just to catch the little F*er. I will never put an angle in any of my reef tanks again. Good luck.