Pros:

- good level design
- very good level layout
- very good item placement
- very good atmosphere
- very good Ai
- 6 maps and not one is boring 

Cons:

- framerate goes below 20 fps sometimes

Conclusion:

 I really enjoyed playing this campaign. I can highly recommend it. From my point of view it's one of five best custom campaigns I'ever played in l4d.