Re: PIty. Most of the stuff I'm interested in is in PDF
PDF is simply compressed Postscript, a language designed for the printed page. Going from A4 to a particular reader size is tricky. It's easiest to simply scale down but this means zooming in and out and scrolling. Reflowing can otherwise be tried but will always involve compromises.
The Sony readers used to contained software from Adobe that did an excellent job of reflowing PDFs to the device's size.
If you really do have a lot of PDFs that you want on a reader then Sony's DPTS1 is the dog bollocks: http://pro.sony.com/bbsc/ssr/product-DPTS1/?PID=I:digitalpaper:digitalpaperproductpage
I think this is kind of device that any of us with lots of technical documentation would like to have.