I’m looking for an eReader that doesn’t lock me into a particular ecosystem or format. Ideally I came just copy files over to it and have them work.
Other than that, small physical dimensions and a backlight would be great!
It’s been years since I had one but in the market again and I’m not sure the current state of things. My old one was a Kobo and took files just fine.
Not sure if this fits what you’re looking for, but FBReader (Android | Apple) on a mobile device is what I use. It can sync your personal books along with reading position and bookmarks using Google Drive and can access any OPDS catalog. It also supports most (DRM-free/unDRMed) formats