I'm not an OpenBSD user (I was briefly, but now use Linux or OS X because of software availability, though I may go back at some point), however, one thing I really like about OpenBSD is the philosophy of doing it their own way. It's very opinionated and I find that to be a good thing. One of the things I find frustrating with Linux is that it tries to be everything, which is good for flexibility, but bad in some other respects. OS X on the other hand has a lot of opacity to me, and I'm not particularly fond of Xcode or objective-C.