I aquire 50/50. I do buy from thier store and use calibre and calibreweb for the other “store” calibre web has pretty good support but you do have to do a very easy config update to sync over wifi. But i basically add to a shelf in calibre web and that syncs to the reader. it just works

I went down that rabbit hole and really had no options that were satisfactory. I average almost a book every 10 days so it needs to just work. I got a kobo libra and love it. Supports all my formats and i sync over wifi with calibre-web

look on github for ytdl-sub. awesome app