Don't know about pros other than if you like their appearance. However, their cons are that they will go after small fish, other inverts (crabs mostly), and will tear at polyps/feather dusters.
Ha! They are easy to dispose of. I will lend you my purple psuedochromis. He makes a bee-line to all spindly crustaceans and beats them up. Except cleaner shrimp, that is.