Pros
As always, the great thing about working for the Federal Government is the benefits. Usually you start a little lower salary wise, but guaranteed yearly step and cost of living increases is great, and if you are in a ladder position, then you get even bigger yearly raises. If you can get along with management and get your job done, they give you support and opportunities.
Cons
The biggest problem is upper management. Generally there is a lack of communication between branches. There is a serious need for resources to be shared and employees to understand how each division works. However, management (despite programs that are supposed to change this) routinely gives excuses as to not hiring employees without direct experience of the job. I support promotion from within, of course, but there is almost no ability to move to a different career track once you are in. Some regions do allow for more movement, but mine is pretty content with having as little as possible.