Pros
Friendly employees, great culture, lots of good benefits and new products coming out. The San Jose campus is massive, with just over 50 buildings, and there is always work going on somewhere. The work environment is also good, and the labs are generally well organized. They also have free soda/tea/coffee, and you can occasionally find free food by going to various presentations. There are also two gyms and a daycare center, and provide great benefits to full-time employees. I accumulated the equivalent of 3.5 weeks PTO per year as a co-op/intern, the same as any regular employee.
Cons
There are too many managers and executives, and endless business/technical meetings which do not contribute much (in fact the most useful meetings are the meet&greet because they encourage teamwork, even though they have nothing to do with your job). Also, the work can be slow and boring at times, and you will not be immune to "burnout" at Cisco. As a co-op, I received no benefits other than PTO and hourly pay.