It is a great map for survival.
We have to stay in constant motion and this feature makes this map an 'Authentic Survival Mode ".
However I suggest you add some weapons and supplies (rifles, molotovs, pipe and bile) there on the 1st floor so we can always be between 3 floors and can play better in difficulty "Expert".
Do not add switches ammo not just add weapons and supplies suggested.
Certainly in my opinion deserves 5 star rating.