Each to his/her own
Interesting amount of thumbs up there, thanks.
I'll sum up my response in one message:
My Windows expertise: present, but irrelevant. That's the whole point, the Mac does the work so I don't have to (partly simply by design). I *know* how to keep a Windows box secure as I've been in this fight for the last 20 years or so, but it's a full time job all of its own. That's *not* what I call a modern OS, even Windows 7 STILL needs anti-virus training wheels to go anywhere near the Net. My problem is that most of my friends do NOT know how to keep a machine safe, so there's no way I will recommend a Windows box for them.
From a usability perspective, it's just different. Some things are better, some things I don't like (lack of cursors, Skype having different windows), and some things stay the same, like confirmation windows popping up where you can't see them so you think an application has hung.
Straightjacket feeling: initially, yes. Until you work out where the controls are. I have on one laptop Windows XP, Ubuntu and OSX, because I thought I needed it. Here's how you find out just how much crap Microsoft finds to replace each week: keep a machine offline for 2 weeks, and watch what you have to fight through before you can work. I actually force the Mac to update every so often because years of Windows has made me nervous :-)
Yes, I do simple Office things on this Mac. It has Omnigraffle to replace Visio, the whole iWorks because I was curious, MS Office because the Mac version is still usable (you can keep the ribbon, thanks), Truecrypt, a whole compiler setup to port some Linux programs I like, a VPN to London because I watch things on BBC's iPlayer when abroad, and I mostly use a Logitech Anywhere MX mouse because I find it easier than the trackpad to draw things. Oh, and did I mention it automatically backs up when I'm at home because I have a hard disk hanging off my access point? It just does it, easy.
So, in summary, it works for me, despite me knowing what I'm doing in Windows, Unix and Linux. To me, that is the only criteria after value for money...