In the absence of any other user testing (see below) I've found that making the videos has been really useful for finding problems.
For example, I've noticed myself occasionally getting confused between the Midi and Modulator sends/receive menus, so I hit upon the genius idea of using a different font & colour for the Midi ones, which actually seems to work...
I'm still desperate for some user testing to report, so please do get in touch. I have to hand in the write-up in a little over two weeks, and as yet have nothing to write about anyone else's experiences. It all works fine for me, but then it would - I need to know if it makes sense to anyone else.
Even if you just 'mail me to say "This thing is crap - I can't make head nor tail of it", I swear I'd still be grateful!
Talking of videos, I posted some new ones: Tonelab as Modular Synth and How to Build Your Own Modules.
(FYI, the distortion in the Build Your Own video turned out to be due to be an issue with my DSP settings, but I didn't want to do the whole thing again.)
Also, in the early stages, I posted a few videos of simple jams, whereas more recently I've tended to tack on a bit of a jam at the end of each tutorial, to reinforce whatever it is I've just been talking about.
For the Modular Synth video, I've posted a separate jam, "synth5.mov" because I was having too much fun to edit it, and it would have made the whole thing a bit long if I'd edited them together.
All three are below.