Earlier this summer I bought two low end AMD64 PCs from DN UK, replacing antique Dells that had just had enough. I've been running Debian as my only OS at home for a year, but for my better half upgrading from Win98 to Debian Sarge has been quite a change.
She is still speaking to me, so it can't have been that painful for her. Thankfully she was already using Firefox on the Windows machine, and was quite use to the general way that PCs work. There have been some niggles, and this weekend's Debian Firefox upgrade did not go down well - segfaulting on any "tab close" does not build confidence. Thankfully I fixed this problem by rolling back a version, and most other problems have been resolved as they came up.
Supporting a knowledgable and critical user can be a real learning experience.