Pros
Flexibility, the sheer intelligence of the people with whom one interacts. It's an incredibly academic yet practical place. It's a great place for new college hires to learn how to think through a problem, come up with reasonable solutions and try their hand at implementing that solution. There is plenty of room for learning, lots of tolerance for "getting it wrong" and it's a great culture to come up with unique ideas. The company is managed bottom's up in many cases which gives associates the empowerment to own something and manage it well. Ideas are always encouraged and everyone has a voice within the organization.
Cons
The banking industry is very tough these days. There is constant concern that one will be part of a right-sizing of the business. There are only two major businesses within the company now: the Card business and the Bank. The Card business is going to radically change as a result of the recent legislation. Capital One was built on the notion of pricing flexibility and fee collection. With the change in regulations, Capital One will have to reinvent itself. It is both daunting and an opportunity for the company to change the very nature of what it does. As long as senior management recognizes that new innovation will be paramount to the Card business' success, it will be a fascinating place to work in the next few years. If the Card business and the Bank can't figure out how to work together rather than merely coexist, then it will be an increasingly difficult place to manage.