Redirect was most maps.... some of which fixed by exiting game and rejoining, can't remember name of ones that didn't.
Everything is too expensive, or you don't earn enough points quick enough.... ran out of ammo and bought more and some health, ran out of ammo again and so had no ammo to kill, no points to buy more ammo.
You lose health too quickly... if you run head on into a zombie in a doorway (whilst being chased from behind) you're dead. There is no way of surviving, most zombies take 3 or more knives to die, by which time they have already killed you. Takes nearly a full clip to kill even the basic zombies.
Prestige levels take up to 50 promotion levels for upgrade..... it's too much and just takes too long to get promoted.
It's a great mod, but it's unplayable with the settings we have at the moment.