My personal take on operating systems is I hate them all and want them to vanish completely. Like the plumbing in my house I don't care if its PVC, copper, or clay pipe because I never see it and regardless of what's in the walls the interface to me is the same. To me the nix's are all pretty much the same and I like it that way. I don't look for differences among them - I don't care to have to care and I've only ever bothered to customize a login or shell in the most minimal way (environment variables is about it). It keeps me portable.

Linux seems too fiddly to me. I don't have the patience for all the little bits of it. The different distros, options, package managers, window managers, etc... Its like collecting trading cards (something else I've never done).

What I like about OS X is it stays out of my way - I install it and it runs. I can install all the open source goodies if I need em, and otherwise it just works and I can safely ignore it. Even network settings and stuff. I can flip open the screen on my Powerbook and if there's a network around I'm on it.

Where I find the fun is in the application development layer. What languages, code libs, are available to make things? On the Mac, Cocoa is probably the most amazing compiled development environment I've ever used. Objective C is a sweet language and the UI building facilities are quite good.

These days I'm retreating more and more into Squeak because the dev tools in Smalltalk are just too amazing (having a debugger you can code in is a treat that I'm missing on my Java gig). Plus the code base available is really amazing (although a little raw in spots). And it really does make the OS invisible with code running bit identical on practically anything with 32M of ram, some persistent storage, a screen and an input device (pen or keyboard).