Regarding the general software experience, even after a year of constant use, I can say that for me personally, a half-decent Linux distro has a lot better usability. I still don't exactly get how Finder works (when does it show me the list view, when the broken folder view with a unnecessary scrollbar - as there is enough space to show all of the icons), the whole app ecosystem is a shock, where it's normal that basic tools (like FTP Client) cost 50EUR or come crippled (Like FileZilla). It's a horrible feeling coming from OSS world.
One UX example I like to show to people is, that on my Ubuntu based home laptop, after connecting Logitech mouse, I get it's battery indicator automatically integrated in the same place with my laptop (and other) batteries. Smooth, no-frills. Something that "the most user friendly system in the world" lacks. And I could go on and on and on... At first I was thinking that it's just the change and I will get used to OS X, but looks like this ain't happening.
I like the touchpad and screen, but I mostly use external screen and mouse anyway.