Pros
Microsoft is a good place to work if you like stability. The salaries are decent, the perks are good (as opposed to amazing). Great work is being done in pockets of the company. Good work to be found in lots of other parts of the company. Reasonable place to work during a recession.
Cons
The average age of people working in Microsoft is 35. This number is growing higher every year. There are many Microsoft couples. This phenomenon brings with itself a certain level of risk averseness. Also, the sheer number of employees attracts a level of bureaucracy that may make it difficult to get things done. Lots of poor/misguided middle management. The same goes for upper management. It is a company that is in adolescence, it's a large , stable ship that has trouble coming to terms with the fact that it has become a typical, large company with all its advantages and standard issues.