Pros
Benefits are good if you are a full time employee. I have had good experiences at Microsoft with understanding groups with helpful team members. With a strong manager at the helm of your group who demonstrates good leadership and communicates with you directly - you will walk away with a very good experience at MS.
Cons
Political obstacles affect nearly every aspect of what you do at MS. You will land on one side of the fence when pitted against your own team wrt performance. Team work is limited by this fact. If you are on the right side of the performance fence it's a rewarding place to work, if not, you will be micro-managed and won't enjoy what you are doing there. Advice: Be willing to work hard and slightly less smart than you actually are so as to not get a poor review. Quality doesn't seem to matter as much as "just getting it done" does these days as the emphasis has changed recently. Contributions are evaluated based on results. Key to getting results is to publicize what achievements that you generated within and outside of your group. Pick your partners carefully as their failures will be evaluated as your own failures as well. Sub-responsibilities that cannot be evaluated easily or at all because your boss may not or can not understand the benefit. Spend as little time on those responsibilities as you can as there is no value to your performance review by spending time on sub-responsibilities you may have inherited or gained familiarity with along the way that are not directly related to your objectives for the current month.