I have the recent version but I have to say I'm not happy with it. While the writing / drawing itself is great, the responsiveness of the UI and some actions (like erasing content) makes the whole experience super frustrating for someone with ADD. It also lacks some features that would make it a worthy Kindle alternative, like structured text higlighting. You can highlight fragments using Highlighter, but it's not smart about indexing and browsing those higlights afterwards, it's just a dumb overlay over the document.