The only crab I like is the porcelain. At this time I do not have any crabs in my system and its been that way for a few years. Back when I had blue leg hermits (2004?) I caught them picking all of the spines off of my large brittle star. It looked like a serpent star until I removed all of the crabs and the spines grew back. I once tried to add a single electric blue leg hermit to my display. It immediately went after a fighting conch so I had to remove it right away.
I also had a chalice frag go from this to the pic below because of a gorilla crab that was hiding out next to it. Once I removed the crab the chalice recovered to its former state.
