Got the initial first round when Microsoft came to my school. I gave my resume to my friend who just started, and he handed it off the the recruiter who then got me the first round. I thought it was the worst interview i had had on campus. My scheduled interviewer was late, so I did my interview with a different person and for only 15 minutes rather than 30. I felt flustered, but I guess it turned out OK.
Once I heard I got a final round, it took a LONG time for them to set up (3 weeks). When they finally set a date, it was past the deadlines of my other offers so I declined to interview. They then rescheduled the interview for later the same week. I had everything figured out only 4 days I was scheduled to interview.
I interviewed with a team based in Beverly, MA. It was much more straightforward than I expected...no real brain teasers, with more behavioral types of questions. Then of course since I was interviewing for a PM, design questions. No coding at all, which was good because I was really worried about that.
I only had 3 interviews, which worries me since I heard you have a full day of 5 interviews if they like you. But it was a smaller team/office, so maybe they didn't have 5 people to interview me. I did interview with senior level PMs. I have yet to hear back, but I'm assuming bad news.
One thing I found is that Microsoft has a lot of resources to help you do well in the interviews. There was a candidate phone lead by one of the recruiters that I found incredibly helpful. I feel like if I really wanted this job, going into it I was happy with my other offers, I could have really studied more about what to expect.
My overall interactions with the interview scheduler weren't the best. They were slow to get to me. Plus, the office I was going to was very confusing and large, so it was difficult for me to find Microsoft's office. I wish I had more straightforward directions. On another note, Microsoft is the cheapest when it comes to mileage. only .36 cents a mile (other companies have been at least .5)