I don't have a Reader so I've never given much attention to this thread. But if the Reader supports RTF why do you feel the need to convert it? (Sure because it displays better.) Just uploading RTF files to the Reader isn't enough? aren't there any formatting tips for making an improved RTF without the need convert it (fonts, sizes, margins... etc)?
(Since my decision on which device I should buy is going to be determined by the RTF readability, that's why I ask you this, specially in order to compare Sony's and Cybook's RTF readability).