I'm primarily living in windows XP again, and it didn't take me long to remember how the user interface used to drive me totally beserk. The back-end is reasonably stable - I do plenty of nasty stuff with C++, and I haven't had that cause a single BSOD. But the front-end - well, it's hideous.
Example: installation of an update causes constant, persistent nagging about needing to reboot the computer. While you're running a big job, it leads to one of those WTF moments and makes you wonder what kind of illicit substance the UI designers were smoking. There are a few workarounds, the majority of which involve ugly registry hacks.
I realise that KDE or gnome aren't hilariously easy to use, but once you get used to them, their crash and burn rates are at least consistent, with most errors not totally fatal. Plus there are a few mature and indispensable features that simply don't exist in other operating systems.
Rant over. This is well worth a look. It's the Chaser lads again - the video from India is worth a look on it's own.