Pros
If you want a super casual no-pressure work environment. If you want to work a really long time at a very relaxed company just to maybe someday get a position where you can throw your weight around to the new people and advance just for participating in a popularity contest.
Cons
There is blatant corruption and emotional abuse. Drama/emotional waste is self propagating due to the nature of the work environment, which means that professionalism is nonexistent. HR is clearly not on your side, that or they are so far removed that they can't tell who is right so they just trust the people in power every single time. If you talk to people in other departments you will notice that these are not isolated incidents. If you want a promotion in a timely manner you can forget about it. They do company-wide promotions and it is extremely delayed, sometimes over a year, as are merit raises. Credentials mean nothing, hard work means nothing, it's all about schmoozing the right people at the right time. If your work style is to work hard every day and keep your head down, this is not the place for you. All the qualified people leave their positions and then someone who is clearly not at all ready gets moved up in the queue. Due to this, the company is like a burning ship.