Dear Stewart, thanks for your detailed posting. However I'd like to add that playing fast single line divisions by for example John Johnson bears (at least for me) a specific kind of difficulty: beyond a certain speed it is quite hard to get an impression of the melody movement in the tablature at a glance. When reading staff notation it doesn't need much experience to see an upward or downward scale or other kinds of typical motions. One wouldn't need to look at every single note. However, when sightreading tablature divisions I often walk into the trap of the unexpected and I find myself playing the wrong "lick" as my fingers move faster than I can figure out all those curly signs. So I think single line music is not necessarily written best in tab like your example of 15th century music with complex rhythm. But then - the time needed to rewrite it in staff notation is better spent on practising the trebles :-)
Best regards, Stephan
