(6) I spent little to no time now on system administration for my own system (compared with 20% of my work time in Linux, with unpredictable breakages)
THIS.
I have been a linux fan since '95 or so, but as I have transitioned from system admin work to programming, I find that linux is high maintenance. Since getting a mac, my efficiency at actually getting work done has skyrocketed because I don't spend time fiddling with the latest window manager widgets. I use linux for servers and testing, but it still can't match the stability of a mac desktop.