tried some more LRF. many of the ones posted here work nicely, but some of the books i've found elsewhere don't look as good. overall, i'm still more pleased with the quality of RTF on the Reader.
i've discovered that Cambria forces the reader to use a serif font, while Calibri makes it use sans serif. 14pt works nicely for me.
also, full justifying text in an RTF makes it full justified on the Reader! the text fills the whole screen, so no messing with margins or worrying about wasted space.
it will take a while to convert and format my library, but i don't read but a couple of books a week, so i have time