Pros
Great benefits, competitive salary (at least at senior level and below), bonus and stock on top of salary, plus additional perks like commuting alternatives (bus pass or Microsoft's Connector service--coach-style bus service from prime locations throughout the area), Prime discounts, competitive parental leave for mothers or fathers. 401K match (or something retirement related) is a must-have in this post-pension world. The Switch from no out-of-pocket health care to a high deductible plan with an HSA was tough, but I personally understand that the former wasn't sustainable. Note that Microsoft feeds the account and for a healthy family with not much more than regular maintenance health services, you can spend less than the company's contribution. This means the savings will grow and be available in retirement years.
Cons
The usual baggage that comes from a long-established company, like overuse of internal tools instead of industry standard tools, as well as entrenched processes and bureaucracies that can hinder agility and efficiency. This, varies from team to team, but several data points I've collected make this feedback relevant. There's progress being made, but in a company this big and old, it takes time. Competing against others who don't maintain a balance between work and life can leave you on the outside, and that's not uncommon here. Working hard and long hours can get you rewarded with opportunities and promotions, and it's hard to argue against this (if you're doing the work, I guess you should get rewarded). It's just demoralizing when choosing not to de-prioritize family can work against your upward trajectory.