Ah but 10% hit for no reason other than to be on the newest coolest os would just make me feel like an apple fanboi who pays X% more just to have apple. Better performance is better performance and without an upswing there's no point to take the hit. Now my video card isn't a dx10 card so that makes a difference to me. If I had a dx10 card I might consider that a trade off. Just as I am considering the trade off of fps to gains in security, minimilisation of virus threats and of course leaving the grey area of my ms product license usage to go to linux.
I don't pay more just to have apple. I pay more because I feel like I get more for my dollar. I don't assess my computer experience based on the configuration specs, or the extra 6fps I get in game.
Ease of use, customization, security, hardware design, and the various applications that run on OS X that I prefer over Vista. I have nothing against Windows machines, infact I own two of them, a linux box, and a few Macs. And out of all of them, I enjoy using the Mac the most. For me, I'll pay more for what I believe to be better.