After playing the maps a couple times, I came off thinking the experience was generally okay. Both maps were alright but had glaring flaws, with the first playing better (IMO).
I really enjoyed how your gametype made humans four hits to kill, because through experimentation that's what I found to be the best damage setting. The issue lied in the fact that the design of the maps simply didn't allow this system to work properly (or at least optimally). You see, to avoid humans steamrolling through to the end of the map (like they did) you have to provide the zombies with opportunistic to score one-hit kills. This can be accomplished through making stealth assassinations easier and adding a tank zombie that with increased weapon damage. What is created is a scenario where the zombie's efficiency, or skill, changes how well the humans fare, and humans need to apply strategies that focus on concentrated fire, as well as watching each other's backs.
The other major point was that the collective progression of the humans wasn't very smooth. In other words, there was a lot of stop-start. Mainly in the second map, humans would travel a very short distance then hold out, only to have another holdout on the other side of the door! Having multiple holdouts is not a bad idea, but you have to make transition areas smooth, interesting, and memorable.
Also, next time try to explore the possible of ending the map with a safe room instead of a holdout. If you want to know why, view and read Aihab's thread.