[heresy]

I used Linux for six years as my primary OS, on OS X for a while now.

On OS X, the biggest annoyance for me, coming from Linux, is the lack of a consistent packaging system.

I don't like the MacPorts style of compiling everything on my own system, but being a Ruby programmer, I'm kind of stuck with it as well due to that being the way any Gem native extensions like to work too.

But really, that's about it.

It's a UNIX. It works. I never have to muck around with my config files, and pray that the next drop of the OS doesn't break my wireless / sleep / wake / sound card.

[grk]

You could try homebrew, which could be described as macports done right - http://mxcl.github.com/homebrew/