Pros
There are obvious benefits to working at Microsoft. If you can hit your targets, you can make a good deal of money. They offer a fairly decent benefit structure and base pay as well, and one can't help but notice the name of a monstrous entity like that on your resume. If you're willing to work, you're going to get paid- simple as that.
Cons
The problem is that it's a total crapshoot when it comes to your team and your manager. If you get a good team and manager, you could easily love your position, as it makes all the difference. If you're stuck with a shoddy group, not only are you not going anywhere, but you'll constantly be floored by the amount of back-door politics and backstabbing that takes place. It's about who you know, not what you are capable of, and after the new job sheen wares off it can be very dissatisfying.