I don't really like the page numbers in the right hand side of ePub files, but I've learned to live with them. Also, in most instances, I'd prefer fully justification as well. That being said, I'm sticking with ePub--mostly because with Calibre I can embed my own fonts easily--and I find I really like the "Fontin" font. You can embed fonts in LRF's with BookDesigner, but this really slows down page turns on my 505. This could work a lot better on the 600 though.
dordale