yeah... I've heard demasoni are total terrors. What a bummer I wanted to get them for my tank I'm setting up but people at my LPS have strongly suggested not to get demansoni with the other Africans I was thinking of. Don't know anything about tropheus though.
well it would be a risk would all depend on tank size and numbers i think. i know i have colony of demasoni and they are pretty mean to each other so you could only imagine if they had another species to pick on.