I've been working as a manager for three years on Handelsbanken on an IT-department. I had a staff of 14 IT-developers that maintained a large system on mainframe. My staff maintained the system in a traditional way. The benefits of Scrum convinced me that I should try it on my department.
When I see the result after working agile instead of the traditional way I'm proud of the result. The result was infact a success.
I don't work as a manager any longer. Nowadays I work as a Projector Manager implementing Scrum. If you do that on Mainframe you have a lot of things to be careful about, it's an art in its self.