Pros:

great object placement
superb pacing
great variation
all 5 maps felt new and fresh

Cons:

can only think of one, the ending

the whole campain was fab, but the ending was just short of also being amazing, not taking anything away from it though, it was still good

Conclusion:

i had more fun plying this than valves own DLC efforts for l4d1 and 2, great job guys, you have many talents, i hope you are making more ;)