I’d like to hear from people who read more on those devices.

I started reading books electronically on my Palm Pilot III, later a Palm V, then a SONY Clie. I loved the convenience of it, especially because I didn't have the shelf space for all my books at home and I'm into 800+page fantasy books that are a hassle to carry around. After reading on PDAs anything is a luxury. These days I read on my smartphone when out and 11inch iPad at home. It's important to manage display brightness though to not tire the eyes, unlike eInk which depends on ambient light.

I generally use Google play books, it syncs across devices and have translation which is good as I started reading French books. But these features are also available on other readers like Kindle.

Interestingly I once worked on an eInk reader for a book chain competing with Amazon. I didn't get any freebie though.