Pros
Cisco Systems is a great place to work and it is getting better. It's a huge company, so it's not all perfect, but when you take it all together you come up with some pretty compelling reasons why leaving the company would be hard to do. Specifically, if you perform well and work hard, you'll be rewarded well. In recent years it seems that managers have directed more of the rewards to those on the team that contribute more. Makes working longer hours worth it. Also, flexibility is a huge benefit in Cisco (remote work, flexible hours, etc). This depends on you and your manager, but if you are trustworthy and self-directed you are afforded much flexibility.
Cons
If you want Cisco to be a fun place to work, you'll need to create the fun. I'm not saying it can't be a fun place but it'll be up to you to organize events and get teammates together.