My personal opinion and I'm preparing to take cover, is that they are normally kept in tanks much too small and with too many large species (normally other tangs). If they have space I don't see them as being difficult at all once properly QT'd. This is coming from someone who ran a shop and has kept many (albeit briefly). I never really had any trouble getting them to feed and maybe only lost one or two to unexplained but (probably poor shipping or acclimation). The same I think can be said about Achilles, I've always found them pretty hardy but only when treated with the respect and tank they deserve.
SDguy- You also have one of the best looking PBTs I've ever seen.
I love that clip. The 2 Powder Blues look so sad after the convicts have moved on.
I know the discovery channel isn't a great source to site, but i saw something that may provide a little more insight to their behavior. They showed a clip of a huge convict tang school browsing on a reef. There were hundreds of them. They swam by a pair of powder blues who vigorously defended their spot on the reef. So, they don't typically live in large groups and they stake out a pretty large chunk of territory and defend it. Many other tang species live in large, roaming schools.it would be interesting to see if those natural behavioral differences match up with other more aggressive or passive tangs.
Keep in mind, I'm using a 2 min clip from a tv documentary for these assumptions. That's hardly solid evidence of anything