Pros
Good compensation (both salary and benefits), exposure to new technologies (everything continuously changes) opportunity to move to different roles (given the breadth of products and number of organizations, there are continuous opportunities for change). Depending on your manager - and out of 7 managers, I've only had 1 bad manager - you are given a goal and allowed to achieve that goal.
Cons
It has become a big company with a lot of overhead and process. Some process is good, but as it grows and evolves the process gets in the way of getting the job done. At corporate there is too much politics. When I started at Cisco, there was a feeling we were a conglomerate of start-ups. That feeling is gone. I've only had one manager who severely over committed the available resources making my life miserable.