Vantaggi
The work you do at Microsoft will affect the whole world, and the people you work with are all very excited about this. All of my managers have been exceptional. There's an overall culture of saying what needs to be said and doing what needs to be done regardless of organizational boundaries, etc. Lots of opportunities for training & development.
Svantaggi
Health benefits are not what they once were, although I'm told they're still very good compared to other businesses. Expect to spend a fair amount of time recording medical expenses and making sure you've been billed for the right services, making sure your providers are in-network, etc. The SDET role is very much in flux right now, since a lot of test responsibilities have been given to developers (not to mention the layoffs). The actual work for that role will depend a lot on which product/team you work on.