I've had one for 12 years in a reef. I have plenty of crabs he doesn't touch. I don't have snails besides those little colonistsa ones, but he doesn't touch those. The biggest issue is that he is a little aggressive to new tank mates for a few days, but he gets over it. Also, they are big eaters, so make sure to have proper filtration.
I used to have 1 a few yrs ago when i had a fish only tank but now i have a reef so a bit undecided..got a coral banded shrimp and some hermits also some turbo snails