My slow-mo switching is not only about the cost, but also about the disruption of deeply-etched routines. I don't want to take time to burn in a bunch of new menus and moves. My eyes and hands already know what to do without thinking twice. So when it comes to my daily work life, I'd rather be extra-adept at an old routine, if it still gets a good job done, rather than learn a new one. It gives a nice illusion of maximum ease and maximum speed.
The mental sense of hunt and peck involved in a new OS or a new GUI puts all kinds of kinks in the seamless flow I get from my old faves. Just call me the Legacy Lady.
I am so hard-over about this, that when brainstorming drafts and sketches in "Back of the Napkin" mode, I still open my older versions of Word and PowerPoint. It is so much more faster and fluid for me than squinting at menus in their '07 equivalents.
In short, I am the kind of user I am sure they love to hate in Redmond.