Vantaggi
Those that work hard and adapt to ever changing metric are rewarded by seeing their results take effect. As middle manager you are able to mentor and reward others. Senior Managers do the same for middle managers.
Svantaggi
Goals are politically charged by significantly external factors, such as every changing public demands. Like any organization there are some slacker co-workers, bully supervisors, and others who will steal unearned credit. If you get stuck with such handicaps it will often be 12 to 24 months to find away out of it. Keeping your head low and consistently submitting superior products will get noticed outside of your group, which helps you move when eligible.