If you already use Calibre and have your master library there, in my opinion, Kobo devices offer a great experience with it.
The Kobo UI lists books in four different (and separated) views:
- by Title
- by Authors
- by Series
- by Collection (that you can manage automatically with Calibre and its Kobo driver plugins)
Then, within each view, you can filter by status (Read, To Read, Reading, Books Sideloaded, Purchased, Download through Dropbox) and you can order by some other criteria that slightly change from view to view (Alphabetically, Reading Date, Date books have been added, by Author, by Series, etc)
The Libra 2 has 32 GB of storage + buttons, and it is a great device all around
EDIT: I always forget the Sage has 32 GB as well

Bigger screen than Libra, worse battery life, pen support to take notes if it's something you need