Sorry to hear that. Hopefully i'll have better luck with mine and get a solid pair from the group. How big was he before you let him go? What was their growth rate like? Sorry for all the questions but it seems like you're the only other person on here besides Mo that's kept them.
Mine grew at a relatively slow rate after the first couple years. I acutally hated to give him up and its one of those things that you kind of regret but once its done its done. If I could have found a female I would have kept him for sure and he was about 9 inches when I gave him up. I tried a few tank mates but he always beat the crap out of the few fish I tried. I remember trying a P. Gibbiceps and a Rostratum that ended badly. I also tried a convict that might have worked but I was always afraid the convict was going to nip his fins so I removed him. I think you should go for this fish because they really are very nice and hard to come by.