I switched from Windows to Mac about 2 years ago and never looked back. My main reason for going to OSX instead of Linux at the time was because Photoshop wasn't available on Linux and GIMP makes me cry. I used Photoshop a lot. Still, I'd do it again at this point.
I found the adjustment period to be quite short, but then again I had been working on both Windows and Linux for quite a long time so I was already used to using multiple platforms and switching between them easily. My Mac experience has been nothing but positive; no defective hardware, software has always just worked, etc. From all the detractors, I'd say I might be a minority. Mac notes:
* There is some seriously great software for OSX. Yeah, you have to pay for it most of the time, but it's well worth it. There are also tons of free apps which are still leagues ahead of their Windows/Linux counterparts.
* The user experience is so much better I actually enjoy using my computer now. No more fighting Windows stupidity or Linux incompatibility / quirks. Well, I still use Linux for all my servers, but that's another story.
* Fusion / Parallels provide very robust and mature virtualization. I use Fusion to run a single Windows app 24/7 and also use it for IE testing. Best of both worlds.
* Specification-wise, stuff is still overpriced. Prices are coming more in line with what you could make yourself, but you're mostly paying for guaranteed compatibility and the OS at this point.
* It seems Apple have had some serious quality control issues recently, especially with laptops. I continue gaining anecdotal evidence that suggests the new laptops are awful. I have an old-ish Macbook Pro which I don't use heavily anymore (though did for about a year) and a Mac Pro; I have never had an issue with either machine.
So there you go. Macs aren't perfect and they aren't for everybody, but I maintain they are a hell of a lot better than any prefab or hand-rolled Windows box (except for gaming of course) and still hold advantages over Linux, at least for those of us who use software not available for that platform. As far as Linux goes, I like KDE a lot and detest Gnome. Maybe that will give you some insight into my opinions.
Just remember: The camp that says there's no reason to go Mac over Linux are just as bad as the one that says there's nothing better than Mac. Choose whichever one suits your purposes better.