Pros
Decent salaries given the industry. Benefits package used to be pretty good, but every year that I worked there they cut a little bit here and there so it isn't what it used to be. That goes for a lot of things. Free software/discounted software at the company store. Name on your resume.
Cons
It's run like a popularity contest in highschool. It's all about who you know and who likes you. If you aren't part of that group you won't get promoted. Seriously. They have this stack ranking meeting every year where they decide it. But *before* that happens, the "in" group of managers that control your team decide ahead of time how they're going to game it during coffee. The supposedly unbiased layoffs in 2009 happened in the same way. Disgusting. Stock that has been flat for the past 9 years. After I left the company in disgust, I exercised all my options and sold all my shares. There was little or no profit after 9 years, which leads to the next item. Poor Management - at all levels of the company. From Balmer down.