Fred - i totally agree
I love the Mac vs Windoze battles, they're so much fun... i've not used anything other than Jaguar and Tiger on my Mac and i would hardly call the differences between the 2 as equivalent to a Service Pack on Windoze.
My girlfriend (yes i work in IT and have one, it's great!) has a G3 500Mhz iBook, running the latest version 10.4.9 without problem at all.... wheras at work i have a 5 year old laptop that crawls with XP and has to use 3rd party drivers for half of it's hardware that don't work very well at all.... sure MS have a harder task dealing with all the variants of hardware configurations, but i'd still rather pay the £129 for Leopard. Also look at the Family Packs, they're normally around £299 for a 5 license pack... given your average family these days has more than one computer at home, this adds another degree of value to the equation.
I won't be buying Vista for any of the computers i manage at work as the calculated upgrade costs for the hardware and the OS is uneconomical... the 3 Macs will have Leopard from day 1 as that'll cost less than a single license of Vista.