Pros
If you're lucky and get a manager who really likes you, it's possible to advance & get a great paying position! If you have great skills in playing politics, kissing ass, talking without saying anything: you'll do well here. You can easily find a group where you do little to no actual work while you get your side business going. Nearly free money. You can pick your schedule, and can work from home sometimes if you choose.
Cons
Unfortunately, the focus of most groups at MS is not making great products for customers. It's largely due to the way employees are rated- measured against peers on a forced curve. It creates an environment of information hiding & backstabbing since there is only gain to be had by watching your peers fail. When it comes to review time, the actual ranking of employees is inconsistent across the company. In some areas it is very much an "old boy's club", while others try to be more objective. The objectivity fails, of course, since it really comes down to how much your manager chooses to fight for you over your coworkers. For your hard-working, heads down developer, expect to get middle-of-the road compensation with low career trajectory. It's simply impossible to do without dedicating a large portion of your time to stroking egos and gaining "visibility". (That's code-word for getting the other managers involved in stack-ranking to like you) The saddest part of working at Microsoft is that it could be a really exciting and rewarding place to work. But the review system is killing any culture for innovation, and management chooses not to acknowledge it. Look at what the leadership does, not what they say.