I rarely see people using it, and its a fantastic weapon, the only one capable of carrying the player through all 3 of the major bosses. (snarbolax is not a "major boss", as you don't go "oh no, I'd better craft a blitz needle to beat the snarbolax", you just use your 1* beast whacker)
Its more usable than the blitz needle is, as you can use the normal shots to light crowds of enemies on fire and the main shot for the same purpose as the blitz. It also has knockback on the charge, which enables it to knock back enemies that are close by as they attack you.... from a balancing standpoint, you'd almost think it to be overpowered. So why isn't everyone using this?
Since all anybody does is FSC, Blitz is much more common than pepperboxes, since blitz is better for FSC.