Pluspunten
The chance to build software millions of people will use while working with some of the smartest people anywhere. Good salaries (especially at higher experience levels) and awesome health benefits for everyone. Microsoft has a reputation for poor frontline management, but there's been a huge focus on improvement that has mostly paid off. Even though the company has 90k+ employees, it retains some of the entrepreneurial spirit of the past.
Minpunten
Can be insular and difficult for those that come in as experienced hires to figure out how to advance and how things get done. Career opportunities are abundant, but it varies greatly from group to group, and while management has been improved it has a ways to go. The bureaucracy has grown into a behemoth and the legal compliance requirements have had a significant impact on development velocity.