To be honest I quite like the Rapier Pistol - the charge attacks are wonderful against Specials by allowing you to do a great head stab, the light attacks are both quick and cleaving, and in general I’ve always liked rapiers because of the “cool-ness” factor they have.
That being said I find the special attack to be near garbage or useless once you hit Champion and above.
The damage from the attack feels weak, the accuracy is absolutely god-awful enough to where you have situations where an enemy within melee range can still somehow be missed, and even as a potential stagger tool against Specials it rarely actually staggers them.
I’d personally like to see some changes to the Rapier Pistol around various areas, like maybe an accuracy or range increase, maybe a small damage increase, just something to make it a little more useful.