Pros
Interesting work, technically challenging and sophisticated. Work with some of the best minds in the business. Compensation and benefits can be decent, if your manager sticks up for you.
Cons
Very poor life-work balance. Poor management, often mandating impossible targets and chewing out teams that can't achieve them. Clash of differing cultures, largely unresolved, leading to a working style of confrontation instead of collaboration. Employees are treated like slaves, or at least interchangeable commodities. There is pressure to not increase head count, accompanied by ever-increasing workload. No bonuses or salary increases in the last year. HR continually tries to stiff the employees, short changing them on salaries, raises and reviews. HR tries to run the business too.