Lots to compare this to
Shoddy research here, el reg. This is turning into the Jesus E-reader ...
"in the absence of anything to directly compare it with" ... erm, how about the Kindle, the Iliad (http://www.iliadreader.co.uk) or the Cybook (http://www.bookeen.com) ???
"touch-screen UI would be a more elegant solution, assuming of course it was technically feasible." ... if you'd looked at the Iliad, you'd have seen it already has a stylus-operated touch-screen. It's not very practical, still very expensive, and charitably best described as a "beta" product and I must admit I didn't bother replacing mine when a friend sat on it. I've gone back to using a PDA. I know ... ancient technology, but it has a quick refresh rate, you can read it in dim conditions and you can do an awful lot else with it.