Pros:

- Theres no where you think is safe in the finale!
- Real sense of never ending
- Loads of detail in everything
- Need to play this with friends!
- Best campaign Ive played in awhile
- Need total teamwork to finish!

Cons:

- Difficult ;) haha
- Nothing comes to mind!

Conclusion:

A proper Left 4 Dead Campaign, would and should be on the game itself!