Mostly agreed, but beware that the UNIX layer on OS X is BSD-based rather than GNU/Linux-based, so it's not exactly the same as Ubuntu or Debian etc.
The biggest win on OS X for me is all the slickness of the desktop (Ubuntu doesn't even come close), and adding easy virtualisation to drop into any OS you want (my choice is VMWare Fusion, but Parallels or Virtual Box work too). Best of both worlds.
Desktops are a matter of personal preference. I am a Linux Mint (Ubuntu with some additions) user. I have used other people's Macs occasionally and I dislike the desktop.
The advantage Linux has is that if you do not like the desktop you can switch to another.
"I have used other people's Macs occasionally and I dislike the desktop."
Same here. I bought a Mac Mini for some dev work, and the UI drives me nuts. It's pretty, but so far requires way too much mousing and clicking.
I'm sure much of my angst is habituation from using a customized Kubuntu install, but as best I can tell those customizations are much easier in KDE than on the Mac.
The biggest win on OS X for me is all the slickness of the desktop (Ubuntu doesn't even come close), and adding easy virtualisation to drop into any OS you want (my choice is VMWare Fusion, but Parallels or Virtual Box work too). Best of both worlds.