Andy, if you don't have a reference point (ie Rodinal without salt), how do you know what the salt is doing? Is it decreasing film speed? Is it changing the shape of the characteristic curve? Etc.
Regarding the artist Thomas mentions (who uses Pyrocat, not Rodinal), I've seen no data. So if it is working, all we know is it works. We don't objectively know whether or not it works differently, and if it does work differently, in what way specifically?
Don't get me wrong, I'm not "for" or "against" stand or semi-stand agitation techniques. I'm just challenging people to think about good testing and some sort of objective data/evidence to support opinions and assertions.
Evaluating the characteristics of a specific type of film processing regimen based on prints is a tricky matter. This is because the end to end analog processes (and materials) are flexible enough that we can get excellent results in a variety of ways. This flexibility is testament to the quality of the materials we have access to, and the skills we can develop as printers. But - it is this very flexibility that makes it difficult to accurately evaluate exposure/development of negatives based on print success. Without objective measurements, it is perfectly possible for someone to think he's getting a certain result in the negative, not actually be getting that result, and still make wonderful prints. With skill and practice we learn to print the negatives we make, and they may be very consistent, but that doesn't necessarily mean we know what kind of negatives we're getting, and therefore we may not describe the results of the process properly.