@ Kepper, anubis88
Thanks

As for save game compatibility:
I have to admit, i did not try it out on a save game. So if you do so, i'm afraid you'll have to do it at your own risk. To be on the safe side, i'll go ahead and say it's not. That way you won't come back here screaming at me that i ruined your campaign that you've been playing for the last 3 months.