Hi Howard,
Thanks for your comments and the link to Appleby's paper. I agree that we shouldn't take the arbitrary cut as epistemologically satisfactory or final: theories may evolve, and this without embracing the ambition to explain everything within one theory. So the epistemic cut I'm talking about in the paper doesn't have to coincide with the Heisenberg-Dirac-von Neumann but between the observer and the observed in quantum mechanics.
Actually, I'm working myself on trying to understand the observer in informational terms, which has been missing from many reconstructions so far. I'm not sure I follow you when you add space and time as conditions under which measurements are "actually carried out". In my view, one of the key lessons of quantum theory is that it's free of space and time - and this is good! Non-locality means that we yet understand only very little about the connection between quantum theory and spatial structures; not to mention that time in quantum theory is only a parameter of algebra automorphisms.
Anyway, thanks for your comments - and thanks for your essay, too, which I read a month ago. I liked it, but I dislike very much the mad situation on this website and the rush for completely ungrounded ratings, so I'm quite unhappy with this contest and the way FQXI managed it. Had I known, I wouldn't have submitted anything in the first place. But for sure we'll see each other soon at some event and have a chance to talk.
Cheers,
Alexei