Pros
You learn a lot and work with very driven people. You'll thrive if you're a workaholic.
Cons
You WILL be overworked. Late hours because they always put the client first even though they always promise a good work life balance. You will get calls and messages during your time off. Or guilt tripped for taking time off. Management and Account Directors will set poor expectations with the client, expecting the people who actually do the work to turn it around same day. If you are not a "favorite", you won't be treated well. Management plays favorites and acts biased. Management is literally people who is new to the industry and been with the company for a long time. They are put into people manager roles and become cocky and act like they're above everyone. While in truth, they don't know how the rest of the advertising and media industry looks like.