Pros
Good pay and benefits. Can be interesting work in the write department. Top level and bottom level workers are good at what they do. If you have good social skills and want to climb up the ladder then there are good opportunities if your face fits.
Cons
Lower management is a joke and more like a boys club. Priorities are themselves, then the project then if there is any time/energy left their staff. They lack of knowledge on how to handle exceptional engineers/people, the ones who come with side effects, so good is the best they will get/keep. The top people at the bottom (i.e. the engineers doing the work) often do not have great social skills and management can't handle them no matter how good they are at their job of for the project.. You have to spend more time looking after your career than doing the job if you want to climb, it's not a place to survive at the bottom level for long. If you want to stay hand's on then Cisco isn't for you no matter how good you are.