Pros
Management allows for a good work-life balance and you can get time off for emergencies. Senior employees are in charge of their own schedules. There is very little micro-management, as employees are trusted to carry out their responsibilities using their own judgment. You get exposed to cutting edge technology and can work on some high profile client accounts. You use reasonably new equipment. You can do your work almost any way you choose.
Cons
Recognition and rewards are extremely rare, as your manager is probably competing with you for them. There's often an initiative to improve career development, but opportunities for advancement remain rare and overall compensation is trending down. People are leaving the company in droves for lateral moves with better pay. Difficult to collaborate with anyone outside your immediate group- most people are too busy doing their own thing. Procedures for getting expenses approved are draconian. You might pay some business-related costs yourself. Although employee-management disputes are rare, HR is powerless to resolve them.