Actually, I think I remember that Rowe didn't bother with routes. And he had some pretty good results. But most everyone else uses routes of some sort; they help make the images or stories stick in your memory.
They way I do it, it's almost impossible to confuse anything...if I solve n cubes I also use n routes; one route for every cube and I'm used to all the routes I use.
I even always use the routes in the same order...no matter wether I solve 3 cubes or 30.
A fixed set of images, a fixed set of routes...the only way to have a DNF is to do setup/moves/algorithms wrong.
Can't really talk about the additional stress-factor during a competition...I guess I would also have memo-mistakes there (just like I did with my Pi-record :rolleyes: ).