It is the 5 comma notation in S&vS that I find particularly bad.
1. It uses a full arrow, which several other notations have used for the much larger alterations of quartertones or 11-dieses.
2. The arrow is vertically nowhere near the notehead to which it applies. This could be confusing in chords.
3. It requires a redundant natural for the arrow to attach to, making it look like a far larger or more complex alteration than it is.
4. It makes for very tall accidentals, causing others to be set horizontally far from their noteheads in chords.
1. True, but in European scores the arrow is widely used for alterations less than a quarter-tone (the quarter-tone symbols having been standardized to reversed flats and half-sharps from the '60's on). What alteration it is, varies from score to score - typically sixth-tone, eighth-tone or just an imprecise small change in intonation. So here in Europe the arrows might be confusing for those who know Johnston's or Kyle Gann's music but that's about it.
2. True, and it happens especially in big or complex chords, but that's more a problem for the composer's sketches rather than published scores, and it bothers me less than the wide symbols and the wide horizontal space needed for combinations of them in Sagittal. The instruments that play big chords do not play from JI notation, anyway, because they're keyboards. String triple and quadruple stops would be the rare exception, and Just Intonation multi-fretted guitars an even rarer one.
3. Yeah. I suppose the arrow could be used by itself as in Johnston; I used the arrow for sixth-tones, in addition to quartertone accidentals, in one of my first microtonal works some 20 years ago. Again, the naturals are what European musicians are used to seeing. And it's been quite common to print a lot of redundant naturals in 12-equal atonal and highly chromatic scores for a century now, so people are quite used to it. It doesn't bother me. For instance, I use the arrows-on-naturals-and-sharps/flats notation for 22edo myself, rather than the mixed Sagittal version that I've made all those Finale demos and examples of for the Facebook groups. I find it looks neater, takes less space and is easier to read and write; in this case I have, obviously, learned the Sagittal version well enough, so it's just a personal preference, rather than a question of being used to one or another. Granted, the Sagittal symbols (only
) are quite easy, so I have no problem of using that when people so prefer.
4. I find them more more pleasing in shorthand than the wide and fussy Sagittal symbols. For chords, see 2. But I'll look at William's drawings, as you suggest.