- It's 10.3", perfect for reading PDFs like scientific papers without being too large to carry around.
- The included reader is stellar, with special modes for reading PDFs, comicbooks, etc.
- The included note-taking app is pretty good and fully featured. It integrates with the reader and there's a side-by-side mode.
- It supports every open format I've tried: PDFs, DJVU, epub, mobi and more. (Haven't tried PS.)
- I can scribble on all document types, including ebooks.
- I can install apps from the app store. In particular this means I can read my Kindle library and Wallabag feed, and...
- with Syncthing syncing is set and forget. When I download a PDF or book on my computer, I simply pick up the tablet and start reading it. Any notes I make are synced back to my laptop.
- Of course, the above is in addition to the standard E-Ink features you'd expect: It lasts for weeks on a charge, the reading experience in bright sunlight is fantastic, it's lighter than an iPad, zero eye strain, etc.
I installed only the software I need for reading and syncing, but there's a lot more you could do with it since the play store and F-droid are available. You can use it as an external monitor, for instance.