Pros
Benefits package is great, especially if you have a special needs kid. Pay is very comparable to other companies, and if you have been around for a few years in a higher level above L63, your annual stock grant chunks and bonus add nicely to your base pay. You work on something, and you have all the latest and greatest tools at your fingertips with a tremendous amount of bright people around you. The campus is a fun place to work especially in the new buildings, and the sports fields are a nice touch. Over the years work life balance has gotten much much better. Changing to "Career stage profiles" for how you track your career growth through different disciplines is still controversial, but much better than some old word doc called a "ladder level guide" that was obscure prone to interpretation issues. This new way helps new employees have a baseline with examples of technical, customer connection, soft skills and teamwork, and other categories for what is expected. Free drinks does not make a job "better", but from what I remember they were a trend setting starting this practice a long time ago and many dot-coms also did this and bested it with free food to boot. We still have full fridges on each floor, nice to have and you really take it for granted if you have been around for a while. Mentors are everywhere and we have a formal mentor program that has worked well for me and many others that I know. Regardless of your tenure or experience, I think many benefit from the ability to pick a mentor and get unbiased advice as an ear to listen to your questions.
Cons
Most hiring managers and recruiters pitch "very easy to move around within Microsoft if you want a new challenge". Well reality is if you are even half way decent, and have been in a team for a bit and are adding solid value, chances are you will have resistance when you try to leave. Or better yet like it has happened to thousands of employees, you actually get "blocked" from interviewing in another team. It has gotten better though in that you don't get blocked much anymore as they finally put accountability on managers to stop this horrible tactic of doing this and now a VP has to approve a "block", so that manager has to explain why you are soooooo valuable and non-replaceable that they can't let you go.