Vantaggi
Microsoft offers very good benefits (except for PTO, which is average), and the employee stock purchase plan, bonuses, and stock grants make leaving difficult.
Svantaggi
I worked as part of a small remote team which had become part of Microsoft via an acquisition. My team and I found that if you don't live in Redmond or Bellevue, it's much harder to feel included as part of the larger team and very hard to be promoted or recognized for your full contribution. They had a ranking-style "bucket" review system that meant that someone always had to be put in the "bottom bucket", an awkward situation for any manager. My team and I found that our manager preferred to put his out-of-towners in those bottom buckets, and it was harder for us to defend ourselves against this action from afar. We had to push to be invited to visit Bellevue or Redmond, and our requests were often delayed or denied, so it seemed like we were held in remote reserve for the convenience of being put in the bottom bucket. We felt like orphans, to be sure. Our boss generally did not like working with remote employees, and we could not have been more aware of that fact. As I was leaving the company, the "bucketing" review system was being phased out, but the overall Redmond-centric vibe in the company is still something to be wary of.