I have one
It's a low priced weapon and when parts break, it's easy and cheap to fix.
That being said, it's difficult to aim, takes a while to break open, and you only have 1 single shot of a small caliber bullet.
I'd rather carry a derringer but my shadow systems cr920P is small enough 8/10 days.
I give it a "buy if you want to waste money on a gimmick" rating.