cheers, Nick
tough to say where to begin here... the issue has been hashed out extensively in more than a few places: RC, wetwebmedia.com, my coral prop book ,etc. I really dont have anything new or interesting to add to the matter on Elegance troubles.
But I can say that mail order shipped livestock are really often the worst/weakest animals to be buying... or at least to be using as a baseline for "health", or not, in regards to an issue like elegant coral problems. Moreover, if you did not strictly QT these corals for several weeks (4 ideally) on arrival to power feed and strengthen them (acclimate to new light from many days in no or low light and even collected at great depth, likely)... then you have had bigger issues independant of whatever may or may not be occuring with Catalaphyllia.
FWIW... I do not subscribe to the bacterium school of thought on the matter, but instead largely agree with Eric Borneman's and others' assertion that the issue is more to do with the fact that Catalaphyllia has been locally overcollected, and that many/most of the current specimens imported are collected at great depth (60-80 feet) where the irradiance is mere (low) single digit percentages of what exists at the surface and they survive by feeding very heavily (absorption and organismally). Add to that darkness in transit for 7-11 days from the point of collection through the chain of custody to finally a dealers tank or your home aquarium, and what we get is a coral weakened by practically no feeding... and very ill-prepared to suffer under full reef aquarium lighting without a proper quarantine and acclimation period.
more to do with proper handling and husbandry here than any other issue
kindly,
Anthony