Pros
Full benefits, decent pay, fun after-work functions (holiday, seasonal), well-funded organization, stability in stagnancy, flexible time management, casual dress atmosphere, gives out occasional goodies like jackets and gift cards.
Cons
No growth opportunities including career advancement, avoidance of promotions by title and pay increases, obvious separation of senior management versus mid and lower level employees, poor functional management, use your own time for corporate meetings if you are 100% project billable (even if you are a company employee), lack of support from functional managers, treated like a contractor even if you are a company employee, projects are silo-ed and rarely does the company utilize existing resources for new projects, no 401K matching, high co-pays for medical and prescriptions, poor HSA plan, lack of structure for moving people between projects, most employees are too "scared" to ask for promotions because they are afraid they'll lose their H1 status, managers are not concerned with your goals or development and only want you to fill a desired role until you leave on your own. You don't get your leave paid out once you exit the company and you can't use leave once you resign. Some managers are too busy to meet with you even if you request meetings because you are not a priority for them.