Vantaggi
It's a job - I was a contractor on various projects at BNYM. I learned a great deal and was given a lot of responsibility on the integration projects I was involved with. People are generally friendly. The Client Service Center cafeteria makes really good sandwiches.
Svantaggi
Not a career - as a contractor, I was treated like a second class citizen, and never really considered for a full time position despite highly relevant previous work experience and a top tier degree. An "old boys club" exists for the actually prestigious positions, most of which are located in or around New York City. Most of the other positions at the company could be done by a trained monkey - BNYM operates in very low value add businesses such as Asset Servicing. That is, they'll store your financial documents in a vault and send you a statement each month.