Pros:

Pleasant scenery 
A variety of landscapes and visuals
Good lighting and colour contrast (e.g - within the hotel area of map 3 I believe; has smoky effect)
Return of intriguing elements from previous campaign (scripted events (explosions) and crafting benches)
Easter Egg
Return of previous maps but with different perspective - making them feel renewed.
Fun gameplay:
                        Good use of lock picking to act as 
                        'buffers' to next area.
                        Tank spawns were always in fair
                        areas.
                        A different take on 'race' to the
                        helicopter - much more slowed down
                        but a lot of fun.
'Custom Boss' if you can call it that.
First map had a good starting atmosphere
Random weapon spawns
Music + sounds
A campaign that can easily be played co-op or SP. 
Raft ride on final map.
The jockey on the children's ride - highlight. 

Cons:

Map 1: Starting area can be a bit annoying if there is a large group of commons - with no melee weapon on spawn a swarm of zombies can easily surround + knock you down on higher difficulties. 
Annoying SI spawns - especially by the crafting bench - will spawn centimetres away from you just behind the wall - usually all 3 SI will spawn there if you are in that room meaning a lot of unnecessary damage is taken. 

Map 2: Crescendo event is continuous - meaning it is unnecessary to hold off with the 50 cal - as they will keep coming. 
Lack of weapons at start.
Trudging through water, crawling through pipes and directional issues means that this map can be played out a lot more slowly and thus being a bit frustrating.

Map 3 + 4: Repeat of areas from before whilst interesting, means that it is easy to rush through and know where you are going.
An abundance of supplies in the housing areas if you look around carefully.
Whilst the sense of exploration was really fun in these areas - it was easy to get lost without any directions. 

Map 5: Boss has no 'damage intake' - would be nice to see him flinch and stop throwing rocks if enough damage was dealt (although knowing how short the 'fight is' perhaps it could be more of a propane cannister stun rather than a long stun)
Boss becomes hugely inaccurate with his rock throwing over time. 
Felt relatively short and little challenge.
Bots are extremely mediocre at the raft event.

Overall:
Vending machine was a bit buggy- sometimes not inputting health when using it
Some areas were easy to get stuck in (especially in the sewers)
Lack of saferoom necessities 
Randomized weapon spawning means you can be unlucky and receive tier 1 weapons
Lack of melee weapons overall 

Conclusion:

This was definitely a step up from your original campaign and it feels like minor issues (and bits of the finale) are the only downfall to this campaign. Would recommend to anyone to play.