Suggestion for future patches:
Make Spies a part of the staff. You can hire 1,2,3,4 etc spies to spie at multiple competitiors at once. Training spies will allow you to copy a part better so you get a higher percentage of increase.
This also allows you to change your tactic a bit since you can focus on getting money and spying on others and spend less money on design.
I also think that this elobarated spying system should only be available for subscribers, even the spying system used now is a nice thing for subscribers to have to "reward" them without giving them a huge advantage.