There's not a whole lot to tell. They'll eat just about anything, they grow pretty big, some are really mean, most are moderately aggressive I'd say. I think they'll all get INSANE when they're in a tank that's too small.
Mine is in a big tank, I've only seen him fight one time in the 6 months I've had him. Very chill. He's in the 6-8 inch range, though, so he's still a pup. This could all change when he hits 10 inches, or 12 inches, and decides he's an adult and he's just not gonna take it anymore--but I doubt it.
I think they're pretty easy to breed, too. If you want a real Midas, you pretty much have to get one from a reputable dealer on the Internet--Rapps at tangledupincichlids.com is a very good source. Dan at cichlidsoftheamericas.com, has 'em pretty much all the time, too.
There are "barred midas", which I like--they're gray with black stripes. Then there's the "piebald" and various colored Midas. I don't like those quite as much, although I'd LOVE to have a solid yellow one. Or Solid white.
They are very thick, very strong fish. They're very interactive. NO fear of the owner at all. They're even kinda playful in a way--hard to describe. I think they live a real long time, too. And I think they're very disease resistant, too. Ya just don't hear too many "my midas has Hex" or "what's this rash on my Midas" threads.
They're just tough, low maintenance, easy to keep, very cool fish--kinda like real big Convicts.