I've had mixed luck with e-readers. I had a 5" BeBook which I liked very much. I lost it on a train, and got a Pixelar. I bricked this, sent it back and have never heard of it again. (My fault, my responsibility.) Then I got a 6" Samsung, which was useful, once I sanded down the ugly, shiny, white case on the front. But, Faustus killed it. And, ultimately, I thought it too big (and didn't like the light color). I was really happy with the 5" BeBook, and was going to just get another of them (80 quid refurbished), but saw that the Opus was going for 50 quid. Since it pushed the major buttons, as It was black, 5"screen, did .epub, and linux based, I decided to give it a try. Although the e-reader experience has been rather expensive for me, I still wouldn't do without one. I would rather give up my mobile phone.
The Opus isn't good for anything but reading. It doesn't play music, doesn't have a touch interface, doesn't have 3G, doesn't have wifi, doesn't have .... However, it is the smallest and lightest e-reader I've ever seen. It is plastic, but it seems relatively solid. It is also very, very fast for an e-reader. I know that I'm happy without a touch interface (indeed, prefer it, as I don't like reading through smudges), but you, like others, may have a strong preference for touch interfaces. I also knew that I was satisfied with a 5" screen from my BeBook experience. (And, I spent last evening happily reading with the Opus.). I would prefer a 7" image coming from a 2" device, but we aren't there yet. (2D holograms would be the way to go. 10 years is my guess.)
Best wishes,
Bob
PS Here's a picture showing the size of the e-reader, and the amount of text I get when setup for reading without glasses (which I use when reading books).
RLF