You Decide.

Microsoft: "Should there be a reason to believe that code that comes from a variety of people around the world would be higher-quality than from people who do it professionally? Why is its pedigree better than code done in a controlled fashion? I don't get that. There is no road map for Linux, nobody who has his rear end on the line. We think it's an advantage a commercial company can bring -- we provide a road map, indemnify customers. They know where to send e-mail. None of that is true in the other world. So far, I think our model works pretty well."
Linux: "It's very simple," said Linus. "Because the software is free, there is no pressure to release it before it is really ready just to achieve some sales target. Every version of Linux is declared to be finished only when it is actually finished, which explains why it is so solid. The other reason why free software is better is because the personal reputation of the developer is attached to every release. If you are making something to give away to the world, something that represents to millions of users your philosophy of computing, you will always make it the very best product you can make. That's the reason why Linux is a success."
i, cringely