Pros
You could make an entire career out of all the opportunities at the Clinic, job-wise. People get in and stay for their whole careers (this is a mixed bag when it comes to trying to do things differently). The Clinic is well-respected externally and will look good on your resume. If you look hard enough, there are some really fantastic people working here.
Cons
A VERY ego-driven, old-school organization. Leaders at the Clinic think they have everything they need, and are often not open to developing, changing, or admitting room for improvement. This is the most political environment I have ever worked in- people can be ruthless and often seem to be pitted against each other instead of working toward the common goal. This is not an organization that will look out for you, or make fair decisions about things like promotions and pay.