It seemed that e-reader screens would converge to 6 inches, but considerably bigger devices keep being produced too.
Amazingly, after new year I still had money left, so I bought myself an e-reader. It turns out that the screen is indeed very nice to have when you read a lot of pdfs and epubs (which I do), even though the devices tend to be short on other functionality. The screen is wonderfully convenient compared to a night lamp and a book, and better than a mobile phone's LCD screen.
Insofar as e-readers are meant to display text, there should be font settings (types and sizes) everywhere. My e-reader doesn't permit changing fonts in pdfs, not even when the text reflows. There's no changing of font types and sizes in the web browser either. There should be.
The web browser should permit saving pages as text or HTML. Web-to-PDF would be nice to have. These things are easy to do in a computer and then load onto the e-reader, but it seems like a natural function for the e-reader itself.
Text-to-speech (and saving the file, i.e. conversion of text formats to audio) should be standard in sound-capable devices. Producers of e-readers should be pioneering the speech software for other languages than English. It's an accessibility thing.
More dictionaries too, particularly from other-than-English to English. And more non-Latin scripts/fonts. Producers of e-readers should be actively developing these things.
Even though e-ink screens have only shades of grey, no colours, there should be colour settings to adjust contrast and such. At least there should be a setting to invert the text and background colours. It's again an accessibility thing. Koreader is a program that fixes this particular aspect on my device, though not globally. Settings like this make sense globally.