Pros
Many opportunities within the company. If you are not happy on your current assignment then it is possible to move to another (at least eventually). In past they have had a good record supporting advanced education. I have no experience with any other employer so my perspective is limited.
Cons
As with most big companies probably, there are many engineers who don't keep up to date on the current technology and the management is fairly risk adverse keeping the proposed work fairly limited and uninteresting. Nevertheless there are pockets of advanced research and development to be found. Recent changes within and without the company suggest the former will be more important than ever -- a con for r&d engineers. The company is also becoming more process oriented which means more bureaucracy, yuck!