Pros
Booz Allen Hamilton has an annual assessement of the consultants working at the firm. It is designed to measure core values, compentency and provides a development plan for the next year. It is a well documented process that gathers feedback (360) from a range of input (junior staff, consultants, vendors and clients). It is reviewd, measured and archived to provide a baseline.
Cons
It poses undue stress on the employee for something that is hardly used in promotion or salary actions. The firm only gives out what that want in regards to salary and even if you get "exceeds" across the board. If you are one of the lucky people (sarcasm) who get to write assessments it is a joy when you are 100% billed out to a client. Most clients do not understand why you are spending hours working on something for the firm. Yes, they give you 8 admin hours to do this but it ends up taking 20+ hours if you do it right.