Pros:

1) Nice atmosphere., very reminiscent not only of  No Mercy but also Crash Course.
2) Very lengthy but well detailed course.

Cons:

1) No health.
2) Few weapons.
3) The bots rarely pick up anything. 
4) The special infected get hung up. You will hear them but they won't (can't?) attack.
5) Some missing textures on piles of pallets.
6) Some ambient sound errors. I was walking on the streets and I was hearing the sound of floorboards creaking. 

Conclusion:

" five grueling maps "
Your not kidding!
If you are trying to give a "feel" of realism; trying to find your way through back allies, running low on ammo and everything else desperately trying to stay alive as your team mates drop one by one.. then the author has done a good job.
If not it's just frustrating. 
Question: why wont the bots pick up weapons and health kits even if they are standing right on top of it?

TL;DR?
Give this one a pass. There are better maps out there.