Matador is a better Felwinter's. Zero reason to use Felwinter's instead of Matador; assuming equal perks the base stats make Matador better.
Comparing to Party Crasher is hard because they're different archetypes with different objectives. Matador has better impact, so it's the king of the bullshit-range one shot. But like Felwinter's, it fires super slowly. Party Crasher has a tad less impact but it fires much more quickly.
The end result is that 1v1, Matador will always be your best chance. But if you want to kill 2 enemies on a flag, something that fires quickly might save your life. It's a matter of preference at the end of the day.
The thread lurk is real.
Time to reinstall