Haha, yeah, I have such a love/hate relationship with that game xD the limb damage is one of it's few redeeming features and I will go on record saying it is 'too bloody awesome for an average game'. But as nice as the damage is, bladed is a poor option, and yeah, it takes limbs off, but its damage on the rest of the model is identical to the blunt weapons, so there's no visual element to help convince anyone to take it over blunt.
Hammers and bats may be weaker then machetes, but they're longer and hit harder, and after playing both, which means dealing with a small group of zombies is actually possible. It means when you swing you got a good chance that whatever you hit will eat the dirt, where as if your packing a knife, you need to get closer and chances are the things not going down until you actually kill. This is a GAME CHANGING difference.
Plus there's other useless choices you could make, like stealth attacks. Your not going to be backstabbing anyone, everyone runs directly at you. The level scaling is one of the worst I've ever seen, as well. It's like every time you get stronger, the zombies get double the enhancement. Your not getting better at all, the game is punishing your progress.