Google has a few more employees.
The idea that everything is shared, and people do pretty much whatever they want is nice, but doesn't work if you want as many heads as Google has.
I finished my contract at Valve a couple of months ago. I'm still fairly early in my design career, and work with a contracting agency in Seattle. I'll be the first to admit that I'm not quite well-rounded and seasoned enough to be a true Valve hire, but I also think I was there to fulfill a short-term need.
Still, it was a great experience. I learned more in that contract than any other, by far. Just thought I'd share some of it!
I wish sometimes people would just tell the story, and not try to distill it down to lessons for everyone to follow.