If you are someone who works for the sake of work, or who doesn't share the 'company spirit' (akin to team spirit, high school spirit, cheerleader spirit) - it will be hard to advance and you probably won't be happy there. There is a sort of 'college culture' of drinking and parties, which the lack of a dress code and campus-like offices contribute to, all of which combined may make you feel like you're still an undergrad.
The blatant expense of the new building (as well as the tuition fees of the neighboring Hult Business School) stands in stark contrast to the salaries of most employees, and there is pretty high turnover in most departments. The structure of the company is like a bottleneck - very few people are at the top, and there are many entry-level type positions with few advancement opportunities.