They are a difficult fish, but IMHO they aren't any more difficult than it's really close relatives, the Powder Blues/Browns/Goldrims. Which, fun fact, the Achilles hybridizes with on occasion
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I think it's just like anything else. Like reviews for online fish stores. Chances are that if someone receives decent service, they not going to blast it everyone online. But someone who had a nightmare with a company, is going to make sure everyone knows about it.
With Achilles, I just think it's more that when someone loses a $150+ fish, they're more likely to tell about it, then someone would loses a $49 Powder Brown...
No special diets needed...