Thomas Shey
Legend
My experience is the gunslinger was awful. They deal pitiful damage when they don't crit, and you simply don't crit much vs bosses. Having random spike damage is probably the worst form of DPS. Any amount that puts the enemy below 0 doesnt count, so when you crit that mook for 30 and he has 10 HP... you only did 10. They are mainly "good"at shooting minions, but because the crits are so random with the spread damage they deal, they arent even reliable at killing them.
We houseruled dual pistols to only take one action to reload and the gunslinger was still dead last in our Outlaws of Alkenstar game. The ORACLE outdamaged me, largely thanks to electric arc and nearly everything being vulnerable to electric and resistant to physical.
I think when looking back over the whole run of the character I can't support "awful", but there are definitely problems with them as they were written. I don't think they're minion-only killers, but there's no question that once you hit a boss you're contributing less than other people unless that minimum crit chance comes up, and you just can't assume that (especially since PF2e combats often run less rounds than a lot of D&D-adjacents do). Your situation is a bit of an outlier from what your last paragraph says, though, so it may have colored your view.