Pistol shrimp

[Alberta-newb]

I have a small pistol shrimp (~ 1.5" ) that came in some live rock and I was wondering what the general concensus is on these? It is extremely shy and rarely ventures more than half way out his home (a 3" piece of rock with about 4 entrances he uses). Google searches have shown mixed reviews, some say remove the predatory little bugger right away and others consider him a cool addition that will form a symbiotic relationship with some goby species.

What do you think?

At this stage I'm leaving him in as I really don't have anything for him to kill other than snails (which he has left alone so far). He does have a voracious appetite if I leave a small piece of food near one of his burrows and will snap several times if I have a tug of war with him over it

Francis