Pros
1. With the right manager, you have access to potentially life-changing career advancement opportunities 2. In some groups, you have the chance to work with people who are the best in the industry 3. If you've got a family and want free insurance coverage for the whole brood, MS is the place for you 4. Casual-dress culture and the tradition that still endures of periodic "morale events" for teams is nice 5. If you're in the right position in the right group, you can get exposure to Microsoft business expertise (even if you're in a technical discipline) that will stand you in great stead in the future
Cons
1. With the wrong manager, there's nothing you can do to succeed 2. If your project goes into crunch mode for the longterm, you could find yourself stuck with 80 hour weeks and no alternative other than to do them or leave the company, because there are ways to hold you on your team if they don't want to let you leave (related to: wrong manager) 3. No raises without a promo, I hear, currently 4. Jobs can be so narrow, and involve so much administrative overhead, that you spend a lot of your time on work that doesn't enhance your skill set or make you more employable elsewhere in the future 5. The company's spending money on what seem to be money-sinks right now, which is good if you want to get into a money-sink team with a fancy title and leave it in a couple years for another company, but not necessarily good for the long term 6. Don't say you were not warned: the same job can be titled and compensated very differently depending on the organization. In general, money-sink groups like search and Xbox tend to offer better compensation than bread-and-butter established groups like servers, Windows client, and Office. 7. Even if you carefully select a team to join based on its manager, which is the recommended way to do it at MS (choose manager first, then job), this can get up-ended by a divisional or departmental reorganization that can give you a manager that is not a good fit for you and there's not much you can do about it