There is a guy here in Memphis who has one of those in a species only tank.
If I am not mistaken that species of Mantis shrimp does not use the "punch", so there is no risk of it breaking glass. They do however have very large pincers "just like a praying mantis".
The LFS has a couple from the things last molt...about 3.5 inches each I would say.
avbryce1 can vouch for me, he's been there. The pic and molted pincers are on the side of the cash register.
I'll try and get a pic of the pic on my next trip.