Vantaggi
I've been a long time employee after starting several years ago right out of college. I have been on teams ranging from amazing to fantastic. There are certainly a diverse set of personalities to deal with but generally if you are not abrasive yourself, you will find yourself immediately part of the engineering community. The shifts in HR policy in recent years have really put Microsoft at the forefront of progressive changes and they do a good job of rewarding top performers.
Svantaggi
Satya's new vision for the company is fantastic and the different divisions are taking different approaches to realize it. As can be expected, some divisions are struggling to make the culture change promised by Satya. Few other companies have as many products and features to coordinate for aligning releases and delivering the customer "pop" that investors need to see and there is an aversion to taking risks after the Win8 debacle so executive and senior leadership seem to continue relying on old instincts and preconceptions for planning and executing. I wouldn't bet against Microsoft eventually figuring it out, but its struggling right now.