Pros:

Challenging yet easy at many parts
Perfect amount of tanks and witches
Plenty of special infected
Mostly quite clear
Plenty of ammo, pain pills and explosives

Cons:

Finale is too easy - the gap between hordes is too long
Special infected locations can be stupid e.g. i saw a hunter stuck behind a fence on the finale
Not very clear at all about how you get out of the sewer, took me a while to figure out you climb up a pipe
Few glitches like on the first chapter the fire extinguisher is floating in the middle

Conclusion:

A challenging and fun campaign although it needs more guidance and a harder finale. Apart from that its a brilliant underated campaign