Vantaggi
Not too much bureaucracy to prevent quick decision-making and add useless workload, even though this is increasing. Good flexibility regarding work hours (you are expected to work a lot including unpaid overtime, but if you need to take time off even during the official working hours there is no problem). On the IT side: you will work on big global projects and gain experience on large-scale IT systems.
Svantaggi
Clearly work life balance is not a priority and the company will get you to work as much as they can if you never say no. In my personal experience this is not too big an issue as I've always had managers who are conscious of this aspect of the corporate culture and try to balance it, but as everything is at a manager-level and non-official other people might give different feedback.