I'm using a 5 year-old Dell Inspiron 8600 which has been my workhorse for as many years. The XP2 is still working fine and fortunately Microsoft still supports it and offers occasional upgrade patches. When I'm in the US it's "networked" with my old Dell Workstation which I reformatted and installed Linux as the OS after Microsoft abandoned Windows 95. During the 5 years I've had to replace/upgrade RAM chips as well as memory CACHE, the R/W CD (they die after a while), and the still relatively large screen is beginning to show some wear (my housekeeper has scratched it by using paper towels and glass cleaner!). I back up often to an older server way far away in another home in another country, in another planet, in another galaxy . . . but the back ups run flawlessly. I dread the day I'll have to buy another PC running VISTA. It appears when that day comes I'll have to upgrade a number of Adobe products, which will cost a small fortune.
My lesbian-documentary-film-maker-cousin is always raving about how fabulous her newest, greatest, fastest Mac is -- and I'm certain she's onto something. But I'm frugal and can't see forking over 3 to 4 times the money for a Mac since I've had to work exclusively with PC's starting back in 1995. However, if someone would like to give me a brand new Mac, I'll gladly take it.
By the way, this old Inspiron is a heavy sucker. I had to buy it its own piece of rolling luggage just to haul it, portable printer, and all the add-ons. Everything barely fits in an overhead bin on a 777.