I've got the Sony and it is okay for surfing from time to time. And I guess you can theoretically surf LJ and read as you go along. But I never really triyed... From AO3 you can download directly to the reader. Generally, you could root it, I guess, then the surfing capability might be better....

pdf work most of the time, but I find epub much more comfortable, so I convert everything (really easy with calibre).