Pros:

+ Original Campaign
+ Hilarious Scares that made me and my friends exited to keep playing
+ A full five level campaign
+ Survivor lines well placed throughout
+ Less linear in some levels, giving the choice of freedom and the feeling of uncertainty (in a good way)
+ Amazing sound design
+ Small scripted sequences that make the campaign so much better

Cons:

- A few invisible props/walls that were meant to be deleted
- Possible to get stuck in a few spots
- My group personally missed where to go at one spot and spent awhile looking
- A few points where items were in the ground/wall
- A few scares were reused or were no longer scary due to location
- Missed opportunity with the "haunted church bell"

Conclusion:

Depending on who you are, the other comments of the campaign not being scary or that the ending is far to difficult can be blessings or curses.  
I, for example, loved the lack of truly pee-worthy scares, as it would have detracted from the L4D2 gameplay.
I also liked the long and difficult ending when played on normal, but found it was indeed very long, surely to long for any difficulty higher.
The "Haunted Church Bell" is a note on the wall mid-way through the campaign, talking about how the church bell is haunted.  I was wanting to have the church bell go off and something really scary to happen, but neither showed up at all.  Seemed like a missed opportunity.

All-in-all, this is easily one of my favorite campaigns for L4D2, and is much fun.  Be the fact you're laughing at a scare that scared a friend, or you're fighting off witches while avoiding ghosts, you'll have a blast in this campaign.  Just play it with friends and with the lights off.  Not guaranteed to scare, but it's fun never-the-less.