I used to like KF a lot, (I have the Bad Santa) but the recent patch just makes it so that without a good team (And I mean a DAMN good team), the levels above Normal are impossible.
They ripped the heart out of the Sharpshooter, crushed the Demolitions and made it so that Berserker/Medic are the only two classes you can legitimately play. Maybe Support.
Simply put, each one of their attacks cripples you and unless you can outrun them - heal, you're screwed.
And the DG teams just sit in a corner with a fire corridor.
Good game ruined by the fans, again.