Pros:

+ Fairly accurate to the ride
+ Backstage areas/gates blocking the flume add variety when playing through on foot
+ Nice to be able to ride the ride zombie-free
+ Seeing Special Infected in place of key characters from the ride is funny

Cons:

- Difficult to tell which zombies are set pieces vs. which are actual enemies when fighting a horde
- Hard to find your way sometimes - took me a while to get past the well/auction scene area
- Couldn't start the finale - button to open the gate didn't respond to being pressed for me

Conclusion:

Very nice. A couple of bugs in the zombie-filled version, and it's annoying sometimes to realize you've been shooting at a set piece rather than an actual zombie, but the ride is re-created well and well-adapted for use as a campaign. Definitely worth checking out.