I had one until 2 days ago.
Sifted sand, but not much. Never ate my sexy shrimp, I had 4 in with it. No social issues. Infact it was housed with a big pistol shrimp (1.5-2") until my Golden Dwarf Eel ate the shrimp.... Then the Goby housed with the Eel??
Seldomly ever left the bottom of the tank. It was in with a Coral Beauty, Eel and some random damsel.