Vantaggi
Microsoft is a company with resources and so if you want to innovate and you have an idea and can "sell" it in the organization, you can get budget and resources to do it. There are some really cool things that the company does both from a product/technology standpoint as well as within marketing. Sometimes people don't see that all because they only have a limited frame of reference from just one or two product experiences. But when you look at what Microsoft is doing to bring access to technology around the globe, or you look at some of the viral marketing campaigns happening, there are some great innovations. Many of the people are really smart and you can learn a ton. Plus the benefits such as healthcare are outstanding.
Svantaggi
It is a very complex and matrixed organization so sometimes figuring out how to get things done is challenging. It's a paradox really where sometimes it seems things get done really fast--a VP snaps their fingers and people jump into high-gear and it's amazing what can be accomplished in short time, yet at the same time because you have to work across so many teams and groups, it can seem like forever to get simple things done because you have to drive so much alignment across groups otherwise initiatives fail without buy-in. It is also a "two-class society" among the General Managers and Vice presidents who live in one realm and the worker-bees who live in another. Rewards are based very much on what you get done, not HOW it's done so often times people trying to get fast-track thru promotions are not actually very good team players.