Pros:

-Canada! Not only for the mention, but the Left 4 Dead Universe doesn't talk much about anywhere other than Eastern US, so this change in terrain makes for an excellent addition, should be canon, somehow.
-OST: This makes for any good map/campaign, a soundtrack that speaks for itself.
-VCs used in the most hilarious of ways, with multiple outcomes for each route taken
-Multiple routes, although not abundant, choice is always a difficult but fun experience for players.
-Original Feel, on a new engine build. Playing though this, the only difference I feel between this and L4D1 is the new weapons, aside from the obvious lacking effects mentioned by the developers. 

Cons:

-The Campaign makes some very unrealistic changes in scenery, and much faster than most campaigns, the lack of progression can often confuse players, especially if they join mid-game
-The lack of ALL the content that L4D1's version had was disappointing, but explained and understandable.
-I can't express how saddened I was when this campaign didn't have a custom finale, for such experienced developers, it seems a bit lazy (for lack of a better word).

Conclusion:

Very good campaign, a custom campaign for everyone's list. This one has it all folks, save a few things we miss from L4D1, you'll want to play this campaign. Get some friends, and some marshmallows, this campaign is sure to be a fun time.