Pros
Global company provides employees with many different cultural perspectives. High energy level of most employees. Opportunity to transfer to other divisions / geographies. Great benefits if you're in Redmond and pretty good salaries. Strong company culture creates sense of community. Great internal promotion prospects. Excitement that comes with being part of such a high-profile company / industry (epic battle with Google, Linux, etc.).
Cons
At times, there was too much bureaucracy...Also, with low turnover rates, the culture is quite insular. Notice the way many job descriptions are written on their job site - many of the acronyms are only understandable if you've been in Microsoft. The concept of 'changing lives' with software was often overblown.
