N.P.
I use the sony e-reader because I'm not tied to a store, I can connect the reader to my computer and fill it with any number of .txt .epub .pdf etc documents as I want from wherever I want. I use the third party software calibre ( http://calibre-ebook.com/ ) to keep track of my elibrary and I bought the wall charger since it didn't come with one for a quick charge if I wasn't near my computer. I use it every night and I've never been disappointed with it. The link below is the model I have. It's dated but I haven't felt the need to upgrade. It's been a real trooper.
http://www.wired.com/gadgetlab/2007/10/sony-pr-505-ebo/