In the interest of full disclosure: I was not offered a full-time position at Google. I was encouraged to apply again after earning a masters degree or after a few more years of experience. Please do not misconstrue this post as sour grapes; I mainly applied for a full-time conversion at Google to improve my Microsoft offer.
The title of this post is hyperbole. Both companies are full of brilliant engineers, managers, and HR staff. Both do an excellent job of managing interns; they really do care. However, my experiences at Microsoft made it impossible for me to choose Google. Both sets of experiences were overwhelmingly positive, but several individuals at Microsoft went that extra mile and won me over in a big way.
Early during my first internship at Microsoft, it was apparent that my skills were being misappropriated. I wasn't having a whole lot of fun and my direct manager quickly identified the problem during one of our weekly 1-on-1 meetings. He radically adjusted the course of my internship to fit my skills and personality. Soon, things were going much better. I was more productive, having more fun, and learning a lot more.
Great experiences didn't end with just my direct manager. Each intern also gets a mentor for additional job and team related support as well as a "coach" from a different part of the company to jump start your personal network. My mentor helped me understand the politics and personalities of our team and team members. My coach convinced me to tell my recruiter about the changes going on with my internship. My recruiter encouraged me to conduct informal interviews and have casual lunches with various people around the company. These "informationals" led to an awesome position for my second internship that was a perfect fit for me.
Internships at Microsoft are as much about growing people as they are about getting engineering done. There are a lot of people around to support you, so you receive a lot of support. If you are lucky -- like I was -- all of these people are exceptional. Even if you are unlucky, at least one of the your many network seeds may be helpful. Additionally, recruiters are more personally involved. Our recruiter took us out for dinner and drinks in small groups and got to know us quite well.
At Google, I once again felt as if my skills were being misappropriated, but enjoyed far less success in correcting it. For the majority of the internship, I only interacted with my direct manager. He lacked experience mentoring interns and was a little surprised when I raised concerns over the quality and pace of my own work. With no one else to turn to, I contacted my recruiter who was alarmed by my frustration. Although my manager and recruiter had the best of intentions, they choose to reassure me that I was doing good work rather than reposition me so that I could do outstanding work.
I am more vocal and assertive than many engineers, and especially interns, at both Microsoft and Google. Speaking up at Microsoft did wonders for my career, but I didn't have to say a word for people to ask "what's the matter?" At Google, I spoke up and I felt as though I was the first to ever do so -- people were surprised and unsure how to react.
It should be stressed that these were personal experiences. Some other fresh college graduate may have a completely symmetric experience.