Pros:

Scarier
More grungy
Looks more like a zombie rather than a cartoon.

Cons:

Skin might be a little too dark, but that's just me.

Conclusion:

Awesome. Pair this with the Beta sound voices for the Jockey, and instead of a laughing joke, you'll take him as a serious threat.

Pros:

It's Leon Kennedy... what more need be said?

Cons:

He replaces Nick, the best of all four L4D2 characters.

Conclusion:

Have him replace somebody nobody cares about.... Like Rochelle. She has no character development, or personality, and her voice is annoying! It's win win!

Pros:

Very well built campaign.
Has it's own originality compared to other campaigns.

Cons:

A haunted place that isn't scary.
Ghosts are just cheesy.
Feels like a kiddy carnival ride rather than a haunted place. 

Conclusion:

It's great, download it. Just don't expect anything scary... really... at all. If anything just silly.