Lol, I don't think I've ever played on that map, I guess it's hard?
It's not, I'd say it's medium difficulty.
Except for one spot, which is bugged as hell and it's almost a miracle for the entire team to pass through it without anyone dying.
Either: a) people get stuck next to the crank, b) the gate opens and immediately closes, c) even if the second gate is lifted, a large group of zombies will pass through it, so it'll close on you and you'll be stuck with zombies on either side of you.
100% of problems with this map are connected with this spot. No kidding
Oh, and if you won't save ammo for that spot, you can as well start again, as it's impossible to pass through without any gun. Good luck!