I had a bad experience with them so I´ll share it. I bought 4 about 5 months ago, they were dime size babies. At first they looked healthy but one died the same day I placed them in my tank. They were "supposedly" quarantined but as soon as I placed them in my tank they developed a sort of body fungus that looks like cotton / whitish things which is very common in Colombian Altums. I had to treat my whole tank and all the other fish survived except for the Altums. All the other fish I had were perfectly healthy.
They were very picky eaters, they would go after every type of food, but always spit it after trying it (everything from flake, pellets, freeze dried tubi and bloodworm to live brine shrimp).
My recomendation is to quarantine them and treat them for fungus, give them their own tank and place plant clippings for them to hide. Tank conditions should be similar to a discus tank in terms of temp and ph/hardness.