concerning Pride and Prejudice, a text directly from project gutenberg is often "un peu brut de décoffrage", in a very basic format (usually .txt or html). that means that you can have hard line breaks (retour à la ligne) which interfere with the correct reflow of the text. if you would like to read P&P i highly recommend you take instead the version
here (with illustrations too !) because it has been formatted in a proper way for a liseuse. the texts from PG often need a bit of work to make them more comfortable to read ; sometimes there are errors from the original scans of the books, and often the format is very basic with no styles for chapters, no text in italic, etc. if you want to learn how to format a text from pg yourself to make it more agreeable to read there are a lot of threads about the topic and if you have any questions feel free to ask ! an excellent and very easy ressource for creating ebooks from public domain texts is feedbooks.com which has a wysiwyg interface as well.
the books from the fnac are already in epub which is the ideal format for ebooks, so they will perform much better in general. the major visible difference at the moment between lrf (sony) format and epub is that epub for the moment does not support justified text. some people find this very annoying ; personally, i hate automatically justified text, as it can present very irregular spaces between words and i find that really ugly.
so i prefer text aligned left. and then of course there is the more fundamental difference of open format (epub) vs. closed proprietary format (lrf).
bonne année à toi, and for the apéro, read again, it is the 31 JANVIER, so if you want to come you are not too late.
fais-nous signe dans le file idoine. where are you a journalist ?