Vista is a poor example, becase there's really not a lot of progress in it. I got it free last year, and am still running xp pro, because many things still have issues with it.

That said, Directx 10 is an improvement over dx9, but the only reason 10 wasn''t made available for xp, was as a 'carrot" to make gamers want to upgrade/sidegrade to vista.

A good examples though are the new improvements added to zbrush 3, Modo, and Vue6 Infinite this summer.. all have some outstanding new features, and they work best on more powerful systems, and both don't fare quite so well on older systems.

Way too many people take way too many things way too seriously.