In my current HRE game my spies have -
- Kept my lands loyal
- Encouraged an English re-appearance in their original lands at the cost of the French.
- Warned of Byzantine, Novgorod, and Egyptian attacks in time for me to move troops to guard against losses.
- Opened castle gates in Flanders, Constantinople, and Livonia.
- Kept my interior safe from Assassins and Spies.

Pretty good for about 150 florins and no upkeep.

mfberg