For a number of reasons, I was recently "forced" to work on an Apple machine for longer than I would have liked. Don't get me wrong: I like OS X, and I think there is a great deal the open source community can learn from it. However, it doesn't seem to be geared up for people like me: 11000 emails literally kill Apple Mail, for example; or, spotlight can be fine for a small home-user folder, but try it on my home directory...
What have I learned from my Apple experience? I learned the power of integration.
Linux is all about choice: there are many, many ways to do anything. The divide between KDE and Gnome is a prime example.