Man, this was rough. It took our squad many nights of attempts and required almost perfect gameplay throughout the whole run! The Sophia steps were BRUTAL, especially if you're on higher rounds. Thankfully we played very efficiently and got to the boss fight around 19 or so. The boss fight was much easier than expected compared to the difficult map, which I guess evens it out. Anyways, I feel so accomplished.
Is this one of the hardest maps of all zombies? I think so, but I admit I'm only familiar with maps from WAW, BO1,BO2,BO3. From those, it seems like the hardest.