Pros:

Beautiful, unique map design. Too be honest, it's one of my favorites. I feel like I am playing through a campaign that would fit in l4d. The final stage feels reminiscent of half life 2 which isn't a bad thing.
Legitimately challenging, it's not "easy" even on advanced. Though there were some areas with a lot of pills.
I actually liked the dark atmosphere, it gives the map a  grunge/horror feel that makes it more fun in my opinion. 

Cons:

The ending is the one flaw. The two tanks are very difficult to kill. However, this could have been because my group had one bot. I think if some pills were placed at the end it would be much more doable. 

Also, the colors change here quite it a bit. I'm mixed on this but it can be a bit annoying when you can't see very well. 

For the ending, I am not sure if you were going for humor or you just rushed the ending but it was pretty lame after such a great map. Either add a cool ending or make it more ridiculous.

There was one area, I believe the second to last stage, the tank was in the warehouse you have to open but for some reason he randomly dies. 

Conclusion:

This is a great and enjoyable map to play that feels like a real campaign because of it's high quality. The ending is extremely difficult so you might need either four people or to lower the settings. Whether you like the ending is up to personal preference but this campaign is still great so it deserves a high score. Best of luck!

Pros:

-Excellent detail, this map really sticks out because of the very unique setting in this campaign. 
-Exploration required, if you like a campaign with long maps and you enjoy exploring the environment this is the campaign for you
-Small areas provide a sense of 'claustrophobia' while fighting zombies.
-The dark and misty areas adds to the tone of the map.

Cons:

LOLOLOLOLOL

Conclusion:

This map is really unique and feels like a real L4D map. The setting created makes an interesting and gloomy atmosphere. Exploring is a must in this campaign and is actually quite fun. There are errors, a few glitch spots, a few teaks required  but it feels like a quality campaign. Please understand that, although the score that i'm giving is a bit low, the setting in this map demolishes any other custom campaign I have played.