Mine does well with a convict but if you go this way be sure to give the convict several Jag proof hideouts for the odd tantrum that the Jag WILL occasionaly throw.
Dovii is right, it is Parachromis Managuense, Nandopsis Managuense is an outdated name for the same fish. Look them up on the net there is tons of info out there.
As for does anyone on here keep them... Well, I think everyone on here has either kept one or seriously comtemplated keeping one, they are pretty cool. Mine takes food right from my hands (large food held barely by my fingertips that is, they have some wicked canine teeth).