Pros
There are some very smart, passionate people working there. When you're on a good team it doesn't seem like work. Employees feel excited and empowered. The pay and benefits are good and many people have their own office.
Cons
Your career growth and rewards are highly dependent on how well you get along with you manager, how much they'll fight for you, and how well they know how to work the system and how effective they are at it. Depending on your organization, there can be a lot of reorgs and your experience and time at Microsoft account for 0 if the leadership doesn't know you. Lately, Microsoft has been making sweeping changes such as "a person must be at X number level to have Y position" despite whether or not individuals have been working in and doing well at Y positions for years. Rather than promote the individual to the new level requirement, they are told they can no longer have that position.