Thinking about this garmin/route sheet thing further, I suppose part of the difference might lie between those people who like to have a sense of place as they cycle about, and those who just do the distances for the distances and are only interested in racking up the miles. That's what ultra-long distance cycling seems to me to be about, and it's probably why it doesn't interest me at all.
I think that ultra-distance cycling is about a whole lot more than racking up the miles (for me, anyway). Its something I'd love to do just for the huge adventure of it all. Take the TCR, think of the places you'd see, the people you'd meet, the long days in the saddle, the heat, the cold, the wet, the hunger, sleeping at the side of a road, dogs chasing you, bears and wolves to worry about!
Those (and a hundred others) are the reasons that I would take on the TCR or something similar (if I could). The miles would be an awesome achievement, but certainly not the main reason for doing ultra-distance.
My dream would be for this thread to document me going all the way to ultra-distance, but let's get tomorrows's 200k out of the way first, eh? Small steps.