That Onyx Boox looks interesting. Especially because it seems to be a BeBook Neo which is readily available here, or rather, the BeBook Neo is a branded Onyx Boox with different firmware (seems to be able to handle less formats for some reason). Although they're interchangeable, if
this site is to be believed. Booxusers seems to be down so no idea how to run the Onyx 'OS' on a BeBook Neo.
Quick question: can you also make notes on PDF files, or only on "books" and, I assume, a separate sketching app of sorts?