Declivis butterfly in a reef?

[i2ik]

I am holding a pair of Declivis Butterfly until sunday so i can make the decision about having those butterfly in my reef tank or not. I asked the LFS if they could put some corals in the tank to see if there would be some nipping, but they told me their fish tank have lots of copper, so its not going to work out with the corals. I have having a 70% SPS tank with 30% LPS and soft. I already have a burgees butterfly that will occasionnaly nip some sps but wont stress the coral until it died. the pair of butterflies will cost me 400$, which is a good deal for those kind of butterfly.

Would you put those butterflies in your reef tank?

PS: I have a QT tank where i could put some corals in to test it out... but its still 400$ that i am going to risk...

Thanks!