I just lost my coral beauty after 7 years, he was excellent with all SPS, clams, zoas and the frof spawn, hammer and trumpets I have had. I have had a flame about a year now and it has also been good.
As you see above, I've been lucky as they are all hit or miss.
All dwarfs are rock pickers and therefor pick at corals for food that is not necessarily the coral itself. This can reduce PE in SPS.
IMHO, they are worth the risk!