In my last job I got a serious crash course in Mac usage (excuse the pun) from literally nothing to having to fix font issues and networking setups on the first day. From my point of view it was a fairly horrific time but I got a lot of experience out of it.
What I discovered was that when Macs, in use primarily by graphic designers, architects, etc, run into a problem, its a SERIOUS problem. I swear to God. I know plenty of people who swear by them and I believe that there must be some point to what they're saying because

of them are practically geniuses in their field, but despite everything I hear about Macs being more robust, I just can't see it. Maybe it's because the users know even less of what they're doing on a Mac compared to a PC but when they hit a problem nearly 50% of the time the solution was either a repair or complete reinstall of the OS which was generally Panther 10.4 at the time.
I can accept that Windows gradually (or sometimes suddenly) builds up problems and errors but in general it keeps on ticking for some time. Mac OSX just seemed to be a disaster.
Didn't know that about the lack of hardware upgradability. Most I ever had to do on em were memory upgrades or hard drive swap outs. HDs seemed to fail

too.
Oh and even though in Ireland, the closest thing I seen to the adds is the spoof one posted earlier, I can say I didn't like it before I realised it was a joke.