I have a question concerning spies.:

What use do they have , why would anyone bother using them?

I just started using them , but why would I want to discover any vices of an enemy commander when I can just built a watchtower in a adjecent province an just read his stats and virtues / vice...


And do spies cause unrest like in RTW ?

Also if you have any good tales to tell , concerning spies , feel free to share them.