I've been keeping them off and on for many years. They are one of those fish I always have to have around. Give them soft, acidic water and surface plants to block the light. They'll colour up a bit, but mostly it's their fins that get longer when they're doing well. They have huge maws for their size and will eat most anything, preferably from the surface or while it's sinking. They'll hit the surface pretty hard, too. They splash me regularly.
The males sometimes display to one another after eating, and it's impressive. They get along well once the hierarchy is worked out. For the most part, they just hang motionless in the water when they aren't eating. If you've ever kept their relative, poecilocharax weitzmani, the behavior is similar, but they don't tend to hide unless there are bigger fish around. It's best to keep them alone or with smaller, slow moving fish.