Leporinus are just fantastic fish. I have got one around 9-10 inches (honestly, I'm not bragging)
They don't show any aggression to other fish apart from maybe chasing them momentarily. I read somewhere that they can be fin nippers, I can't honestly say I have had that problem with mine. All in all, fantastic tank mates for any fish. Their mouths are very small so will only be able to eat only tiny little fish so won't pose any risk. They don't take food from the surface, only normally from the bottom, they love small pellets, bloodworm, kril.
I found them to be very skittish fish that are spooked very easily so no sudden movements when they are close to the front of the tank.