Pros:

Obvious that a lot of work was put into this map.  Long Campaign and difficult to beat on Advanced level and above.  In fact on Normal level there are some very rough spots.  But I would not call it unfair. Pick your playing partners carefully, you will need skilled help.

Cons:

Only Con really might be the overall length of this if you are not prepared to play for a while. 

Conclusion:

Hard to complain about this Campaign when it is obvious so much effort was put into it.