Vantaggi
You'll get big responsibilities and opportunities if you want them. Although your salary won't grow much, top performers will see their bonuses and stock rewards surpass it.
Svantaggi
Very little professional development is available - you better be trained before you start the job because you won't have time to get your training elsewhere either. You'll only get promoted if you befriend Directors and above or work so long they feel sorry enough for you that they finally promote you. As a result, most competent people leave to grow their skills elsewhere and only those who can't get a job elsewhere stay to rise into upper/middle management (e.g. most Directors, VPs, and at least half of Senior VPs are incompetent). A lot of smart people in the bottom of the org, and a few smart people at the top (e.g. Jeff Bezos) run the company and often bypass people-managers in the middle.