Pros
As far as giant mega- multi-national corporations go, Cisco is the most benign. On good days, I actually believe that Cisco is doing things to make the world a better place. Even on bad days, I don't think we're doing anything to make it worse (not on purpose anyway). Cisco is a company that you can feel proud to work for.
Cons
The same can probably be said for most companies, but direct line management can be extremely weak. There are inconsistencies (in marketing anyway) in the ways that people are treated, whether it's moving up, down, or out of the career ladder. HR has been incompetent for years, but it is actually getting better with management change in the last year or so. Then there is the issue of some senior management personnel who demonstrate outright disregard for the company in the sole interest of furthering their careers. Again, I'm sure it happens everywhere, but it's more disappointing at Cisco where the CEO and most employees have such high standards and expectations.