Pros:

Challenging puzzles
So many memorable and OMG moments
Very unique
There is some randomness in each chapter
No nav or brush errors (that I came across)

Cons:

Not practical in single player?

Conclusion:

Just when you think things couldn't get any crazier, the next chapter goes and tops the last!  A great campaign to play with three of your friends, especially if you're into puzzle and traps.  The only problem I had along the way was at the end of chapter 1 (having trouble getting across the bridge), but after that it was smooth sailing.  Overall I would VERY HIGHLY RECOMMEND THIS CAMPAIGN to anyone wanting to play a puzzle map with some friends.  Great campaign!