Been using Mac since system 6 OS, and occasionally forced to use a PC, but I never bothered to remember which version of windoze. Mac OS 10 is the most stable OS I have ever used. Blows away all previous mac OS's and anything windoze can dream about. Oh yeah, and then there is the money you will save by not buying virus protection, not to mention the bother.
Another point, I have a four year old iMac, it still performs up to par for my needs, and still works well with the current OS.
Mac products are freakin cool too. The only reason people use PC with windows is because that happens to be how they were first introduced to computers, and they just got used to being abused by their PC, they think it's normal. They will rationalize, like an abused spouse, it's not his fault, I made him mad..... oh, I guess I shouldn't have installed that new cool sound card..... They just need help, and understanding, and a little love. Would you rather get a hug from Steve Jobs or Bill Gates?
best of luck, JBY