Very nice product, great setting with a lot of neat flavor. I used bits and pieces of it to flesh out a library-ruin-dungeon in my home game. It was nice to have another source for random books on the shelves, some knowledge based boons and some inspirition to help get me in the mindset to run a library dungeon run.
Slight caveat for DMs, some of the magic items are strong for the rarity. Specifically, the Expeditious Tome and the Magic Tome are an outright improvements over the Wand of the War Mage (+X to spell attack rolls AND to saving throw DCs vs +X to spell attack rolls). The ability to boost saving throw DCs is very powerful and acts like a force multiplier on a lot of spells. Good items, just be aware that if you hand it to a strong mage, they might land significately more spells.
[5 of 5 Stars!]