Pros
Really nice atmosphere, cool office, employee discount, nice work-life balance, lots of opportunities to learn.
Cons
there is no such thing as flat hierarchy. There is a very clear "discrimination" of job grades: you are not invited to many meetings (sometimes not even allowed to go), which reduces your chances of exposing yourself and getting credit for your work. I delivered a lot of great, deep analysis (I know that because my lead told me so), that were used in several meetings, presented (only I did get to do so), and useful to business decisions. It is a recurring feeling of being used: you just give and you only find out you did great, if you insist (and I mean it) on asking it. Leadership is unprepared and not enough developed. This company is every men and women for himself/herself.