I have to work on an latest-gen iMac at work because that's what they bought us. I tried for over a month to get used to it, but it's just too much crap that accumulates. I waste too much time on things I shouldn't even be thinking about.
Such as alt-tabbing doesn't cycle through the windows an application has, just the application. If I have three Sublime Text 2 windows open, I have to hunt it down like a predator.
So I just installed VMWare, and setup my Linux Mint 13 machine and work there exclusively now.