First try

I played this map once under the impression it was going to be similar to a normal difficulty No Mercy run.
Turns out there are variations of differences which I did not expect. 
To those variations I did enjoy, and some I find could define cons.
The list I have are from my first impressions; therefore,they are  changeable if I played this map couple more times. Don't take them too serious.

PROS:
+ There were removals of shortcuts or cheesed areas that cannot be reached anymore. Ex: 1st map - The two fan conveyors, the opposite ledge at the starting apartment, and pressure thingy next to the car below were removed.
+ Balanced brightness in areas that were dark in the original map. Ex: Sewers, apartments
+Nice little tribute/secret of Turtle Rock Studio
+No Tier 2 weapons at the safe rooms until Rooftop. Players may have a different opinion on this, but this is a good idea to punish those that have died along the way to the saferooms.
+Textures are well detailed. Ex Cars, walls, pillars, elevator.
+Variations of different props and locations area nice thing to see. Ex: Medical cabinets shifts location shifts, the clothing store.
+Thank you for having the wall collapse next to the usual corner hold of Hospital during elevator crescendo. It only breaks in versus mode or survival mode in the original l4d version.
+ Pillar @ start in Rooftop
+Rope ladder to the helicopter
+Molotov alarm isn't necessary but tis a fine sound to know you're getting burned infected. :)

Cons:
- rip burger tank
- Takes a few seconds longer for the horde to spawn from crescendo. Ex: Car alarms, gas station explosion
- On Sewers: I felt there should've been another ammonium pile between the arrival of the gas station to the drop of the vent. I was using an m16 and went back to the safe room twice for ammonium.
- On Rooftop: The increase height to the lower division and buildings makes it very easy to get ledge incap from a simple jump. You have to be almost precise to use the ladder to go down the lower division. Overall I had to be careful where I leap.

Overall, amazing job on this recreation! I was brought to another vibe when playing. I hope you and your teammates continue in more projects like these!