Quite agree. I have a Diamond Rio500 (cant remember how old, 12 years?) that I use for portable music/audio books. It is not much bigger than an iPod, takes 1 AA battery that gives many hours life and it bookmarks both Audiobooks and music perfectly amongst many other functions. Playing MP3's on a Hanlin V5 or V3 reduces the battery life to as little as 5 hours. Why would you?
Ebook readers are for reading and you will love that.