My trimac way back was a terror. He would bite the crap out of you if you weren't paying attention, but really about the same as most big amph's. One of the best fish to keep imo.
One thing I'm concerned about with mine is the color. He's also in a 360 right now with 9 or so other male amphs,7 or 8 of those are bigger than him. Would that be why his colors aren't popping?