Ok, so, as long as I have my ancient sony working, why should I buy a new reader? Well, that's a question I'm asking myself now.
The only reason I wanted epub3 was because of how it handles notes, the possibility to open notes in-text, without having to go to the notes at the end of the text and then manually return to where you were, which takes me out of my reading flow every time.
But yesterday I was checking out a new version of amazon kindle, and one of the things they were advertising was precisely that, notes will open in a pop-up window and one can close it after checking it out. So, I am now considering to get one of those kindle tablets, instead of a kindle e-reader. Then I could read texts without notes on my old sony reader and read texts with a lot of notes on the kindle and also use kindle for other purposes. Sounds like a plan to me. Especially if I can get one of those very high resolution new ones. But I've read some complaints about blueish edges. Hmmm.
Anyway, thanks for your answers, I appreciate it!