Pros:

original design, models and idea.
really immersive design, (puts you into the game)
great changes to the sewer area
fantastic flow of play, (easy to follow through without getting lost)
Ambience was exquisite
original finale creation(explanation of issue in conclusion)
great use of varying paths(some games it changes at the horde pile(factory!?!) fence that makes you alter your path!
sewer plant 2 (where the gate opens and alarm sounds), improved: old version had a ladder to climb now it is a set of stairs.. perfect!

love the finale where you have to insert tanks to get the train to lower(spoiler**) but yet an original idea none the less!

Cons:

the altered path at the body pile and tower, second map, had some troubles getting stuck crouching out tower windows(though well marked) to climb down wood plank pathway. (minor annoyance)

other than that.. no real cons!

Conclusion:

This campaign is superb in its originality. this is a favorite of my wife and I for some time, even since the beta days.

known issue**  Use of super hordes v3 messes up the finale to the point that the guy who is supposed to throw tanks down to you to lower the train doesn't appear. he will acknowledge that the system has crashed and the hydraulics are broken or not working. CAREFUL WHICH MODS YOU USE, THIS COULD AFFECT FINALE SCRIPT TO MALFUNCTION!!! This isn't any issue on the part of the developer, just conflicts with the finale script...

openings in the floor open and under the train to place these hydraulic tanks into place to get the train to lower. The entire campaign is well thought out and original. I understand it took the developer some 2 years to complete, improve and alter and time well spent! this campaign is tied for 1st place in my favorite campaigns along side of bloody moors. This is a must have on any server!