lion (or buffalo) heads are hands-down one of my favorite fish out there.
i can speak from my own experience with them and from what i have read about them, but as always YMMV.
IMO, they are quite placid towards FISH THAT DO NOT FREQUENT THE BOTTOM OF THE TANK.
if they have to share the bottom territories with other cichlids, FW gobies, etc. than IME they can get quite aggressive and hostile.
a lot of people that i have spoken with like to keep them with congo tetras, since congos are larger tetras that pretty much stay at the top to mid levels and will give the lion-heads all the bottom territory they want.
plus, they both are african species, so if you are a die-hard purist they fit the description.
yeah man, given that you dont keep them with other bottom dwelling fish you wont have any problems with them.
M