Ebook readers

[Shearwater]

After reading an interesting article about a new ebook reader from Sony about to hit the shelves in Germany in October, I am seriously considering to buy one myself. It's something I have wanted for years, but to be honest, I don't really know how these things work and don't know anybody who owns one (please excuse my ignorance).
First of all, how does it work with the DRM system on these things? I was really surprised to read that it's apparently no big deal if you simply want to read your own PDF or .doc-files with it. I've always thought that these things were restricted to display only files in some proprietary format so you would have to buy your ebooks from a site that sells them. Since book prices in Germany are the same for both the printed and the electronic version due to legal restrictions, ebooks have never seemed particularly attractive to me.
Also, I can remember that I've read something a couple of months ago about Amazon deleting content that customers had legally downloaded onto their Kindles. (I'm not considering to buy a Kindle, for a whole lot of reasons.)
Finally, display quality. Does it really come close to reading a printed book? I hope that it's different from reading my PDFs on the computer, which I find is somewhat straining to my eyes.
So if anyone could post their experiences here, I'd be really grateful