> The kobo sync with calibre-web is only for books. You can choose to sync your entire library or just a specific shelf. You add books to that shelf and sync, it will make sure the books on that shelf are on your kobo.
>For syncing reading progress across devices KOReader is apparently the way to go. You can setup syncing on there and any device that has KOReader installed will have the same reading position.
I'm using calibre-web + Boox Darwin. Maybe not as functional as some other solutions, but you get a great personal library and books sync over opds. (Not progress sync, but I don't really need it)