Knoppix definitely isn't a great beginner distro. But just for a usability perspective, ummm...
When's the last time that you put in a Windows CD and got to test drive the entire, working OS? Or had XP running off a USB key?
Maybe I'm missing something, but I have difficulty with this. One of my best friends is a Computer Engineer, and he and I go round and round about it (As I use only OSX and Linux, and he uses only Windows). He starts off with "Well, it's missing basic functionality" and when I reply where those assumptions are either out-of-date or just plain wrong, he starts picking on some obscure functionality that took him time to set up in Windows that he thinks should "just work" in Linux.
It's as if the OS cannot be as competent, but different - it has to either offer every possible solution, or it's worthless.
Not meaning to have a go at you, Kougar, but if you read through your posts with this thought in mind you'll catch it even in your own (more intelligent) ramblings. Most things in Ubuntu and Mint are completely ready-to-use right out of the box, not even any drivers required.
Before you can even USE Windows, you have to go through a full install, then run the motherboard CD (which may or may not be handy) to install chipset drivers just to get your networking up in order to download: sound drivers, graphics drivers, updates, power management, RAID drivers, SB/NB utilities...
And THEN...
Winamp (or whatever you fancy), VLC to play more than like 2 formats of movies, codecs for everything, quicktime, a decent web browser, flash, adobe reader ...
before you can even use the system for BASIC web browsing and media.
Whereas on Linux Mint (an Ubuntu derivative), you...
burn a live CD, put in disc drive, boot. The end.
So...Which is lacking functionality and user simplicity? *scratching of head...*