I finally had a chance to listen to the St. James videos with the Micro-Seiki and the American Sound 1000. On my desktop computer, so ... a rather analytical take:
With the AS 1000, I could easily hear more harmonic information, more nuance, from the rythm section (espec. baritone sax, clarinet) and from the 'moaners' before Armstrong starts singing. There was one particular standing bass pluck near that point that was particularly wealthy.
When Armstrong starts singing solo I have a greater sense of his 'presence' v the M-S - though it was not missing there. I don't want to describe that in terms of dimensionality. It had the same impact as I heard from listening to Ella standing before us singing 'Take it Easy' at David's in Utah, but just slightly different - Ella was there there. Not sure how this was recorded I don't think he was in a booth - struggling a bit to get this right ... when he was with the moaners for just a few bars ("yeah yeah yeah", twice ~ 1:32) he is integrated, then he splits away and slips into solo. Armstrong is individuated as the moaners are not. In this case I do not have a sense of him in front of the band as Ella was next to her guitarist, more so of his head. A wee bit of the recording process peaking through or just me.
I find this sense of 'presence' (there-ness?) a key contributor of natural character of the sound.
And lawdy that final cymbal strike goes on foh-ever, 9 seconds? It's all a great treat - thank you Peter for doing this wonderful comparison.