IMHO, Apple builds the hardware and the software to run that hardware, by selling the whole package (nice design included) they are probably the best at optimizing their product, im very sure you wont buy a Mac if it didnt have such a well optimized OS.

Windows on the other hand is just an OS, IMHO it is quite unfair to compare it to Mac OS as MS Windows is built to be used on all PCs whilest Apple has a purporse built OS for its hardware.

Regarding PCs needing constant upgrading, my uncle was using a 486 DX100 PC for 10 years, only upgrading his HDD once, he uses the PC to do word processing and emailing. Unlike a gamer which constantly needs to upgrade his/her PC to cater for maximum performance(this could be compared to modding cars to get a few extra horses), my uncles PC served him well as advertised. Fact is the mac isnt really just a word processor isnt it? IMHO most people buy Macs because they need a machine for photo/video/audio editing and so on and Macs provide them with that capabilities at least that was until Macs became fashionable to own and everyone wanted to get one.

IMHO both windows and macs have their pros and cons but it depends on what you want to achieve by using/owning a Windows PC or a Apple Mac.

IMHO i think Mac freaks are equally zelous about upgrading their macs.

I do plan to own a mac one day too but it makes practical sense for me to buy a Windows PC now as i am a windows based programmer.