Pros
I was in an internal project, i was insulated from all client pressure. They don't force you to be there at office for 8 hrs. If you finish the work you can go home. Nice saravana bhavan south indian food, bit costly though. Lot of new hires, especially ladies to see if you are bored :). GYM. Transport. Lot of fun events.
Cons
You don't get to choose the technology/platform you work with. They will force you into something. Even good computer science students with good knowledge go about doing grunt copy paste work. Poor academy training. If you are a fresher don't expect to get challenging job for first 2 years. Everything depends on your manager and project. Only programmer analysts and associates write code, other refuse to write code and say they are into *managing* people. You will see lot of "pointy haired bosses" who do not understand the nature of technical work you are doing and yet try to manage you. The work area is totally noisy, the managers will be in calls all the time. Not good for programmers. For laterals they will ask to do a lot of things, you might have done sharepoint in your past, they will ask you work in windows applications.