I'm such a boring person. After using OS X for two seconds, I took out the colorful background and replaced it with a single plain color, moved the animated dock to the side to get more vertical space, got rid of all the iLife apps from the dock, and set up keyboard shortcuts so I don't have to keep using the touchpad so much.
The thing that throws me off the most about OS X is how much reliance there is on the mouse due to the lack of shortcut keys to reach the menus or buttons directly. e.g. in Firefox for Windows, if I want to go to the web search box, I can use the shortcut key of ctrl-K, or the IE-style ctrl-E, but if I don't remember those keys, I can easily press Alt-T (Tools), then either press S for Web Search or use the arrow keys to pick from the menu.
The second type is if the menu has no direct shortcut key, e.g. Firefox for Windows again, if I want to go to the Add-ons menu. I can do Alt-T (Tools), then A (Add-on). On the Mac, I would have to use the mouse since there's no shortcut key for Add-ons. Yes, ctrl-F2 can open the menu, but it doesn't open to a menu item directly, and then to open a menu item, space bar has to be pressed. For that many keystrokes, I might as well go for the mouse in the first place.
I did use a Mac long when I was in school, but I thought that with all the evolution in usability and operating system theory, plus OS X is a Unix-based OS, I should be able to do things faster by pairing the keyboard and the mouse.
The second thing that threw me off was OS X applications were not compatible between versions of OS X! That would explain why my OS X using friends were always explaining to me that Windows has compatibility problems. But for OS X, older versions of applications simply do not work or do not work correctly with newer versions of the OS, so when you're forced to upgrade your apps, there are no compatibility issues!
And while starting to type this blog entry last week, I suddenly noticed that the mouse pointer disappears while typing. After a few days of searching, I still haven't been able to find a way to change this setting. This also explains why I see a lot of Mac users "shuffle" the mouse whenever they pick it up.
One other annoyance I noticed is that holding down the shift key to select files in the Finder doesn't work as expected. If I overshoot my file selection, I can't press the opposite arrow key to deselect the last selection. Pressing the arrow keys always selects files from the original cursor location when you first held down the shift key. Incredibly annoying.
Oh, and my biggest problem with switching to OS X? Whenever I encounter a problem or something that I don't know how to do. I hit Google to look for answers in public forums, and almost always, legions of Mac fanboys would reply with things like "If you don't like the way OS X behaves, go back to Windows!" or "It's the Mac way! Learn to deal with it or go back to Windows!" I could always find others asking similar and legitimate questions, but was never able to easily find solutions or answers to my problems.