If you haven't tried Linux recently, it's actually gotten pretty good on both of those fronts, especially if you compare it to Windows. Also, many PC manufacturers are starting to pre-install Linux, which should make it even easier for people who don't want to worry about installation.
I'm just saying... the whole "Linux is too hard" argument doesn't hold much water with me anymore, since both my wife and 8 year old have been using it with no problems for a while. =)
But yea, OS X does seem pretty nice, I'd probably give it a try if I didn't care about things like openness [1] and vendor lock-in [2].
MacOS is a nice Unix in its own right, and if you really need to have Linux, it runs fine under Parallels. I've got Windows XP, Ubuntu, and the One Laptop Per Child project images on my MacBook, and can boot any of them depending on what I want to check out.
I use almost all free software. I do all of my work under the MacOS unix environment with vim, gcc, python, etc etc. You can use the MacPorts ( http://www.macports.org ) package manager to install and manage your usual unix utilities. (MacPorts is analogous to portage/emerge on Gentoo, apt-get on Debian, yum on RedHat/Fedora, and FreeBSD's ports). I also use Firefox for web and Adium X for IM.
The only thing I can recall paying for is Parallels, a virtualizer similar to VMWare, to run MS Windows under MacOS. I hardly ever use it.
