Thanks for the Janacek, Jack. I think i've heard our horn section playing that actual version!! And I'm still giggling even after reading the rest of the thread!

I learnt notation nearly 70 years ago, so found it difficult to understand the purpose of ABC, other than for transmitting tunes via text on forums like mudcat, where its advantage is that no provision for images is needed. And as it used so widely it's worth the effort of learning.

I see it as having the same relationship to notation as the guitarists "G7" type notation has to a figured bass. ie it refers to actual notes, rather than intervals.
Does this make it harder to transpose, particularly at sight? or do you get used to eg thinking "Bb" when you read "C". Although as guitarists transpose (but only upwards) by using a capo, and mentally playing (so I believe) the original chord, is this mainly a question for melody players?.

The advantage of notation I find is that it shows the pattern of the notes; and is easily transposed, either by mentally shifting the whole pattern up or down, or by changing the clef; and so is an natural development of the cryptic markings over the text in plain chant (which I think continued in baroque music as representing ornaments)
But neither format is so prescriptive that it leaves no room for individual interpretation.
While writing on the back of whatever is now used instead of fag packets is mentioned, It is self-evident that mudcat members have pc's, and so probably printers. And so no excuse for not having a bit of MS paper in the instrument case or back pocket!

As an aside - Transposing in midi is a simple procedure (if you can code - I can't), just change all the pitch values by the same amount. Changing mode is a bit more difficult. And despite midi's bad name as having a "mechanical" sound, this is only when it's produced by transcription from notation. Files produced by live performances will replicate the nuances of the performance almost exactly. I don't think I'd consider trying to read a midi file on the fiddle though.