Vantaggi
Great benefits, delicious food options on location and around area, good place to try and network (when people are available and not traveling :) You are never board because there is always a task to complete and some urgent matter. You become a jack-of-all-trades if you are a C level assistant.
Svantaggi
Major drawback is that you can easily become "stuck" if you are an assistant at the "C" level or lower. It is very hard to break that ceiling because management always sees you with that title on your forehead (especially when applying for jobs w/in the Bank). The fact that you have knowledge, skills and have gained a BA, Master or PhD while at the Bank doesn't matter. WB management still prefers hiring outside. A manager told me it's because there is a belief that Bank employees at that level don't know how to do the job and they rather just choose someone new who is easy to mold.