Strengths: Creative and imaginative. Wide and deep. Actionable and flexible. Character options are embedded, related and unique.

• I appreciate the case study style discussion, like the bit on armor and crossbows
• Ancestry (species) lore and guidance is clutch, especially as this list is always expanding
• I already had some sense of the Tairnadal elves from novels - I'm pretty meh about the murder cult violence-is-prestige society types but they're explained effectively and given a bit more dimension
• Both sets of Gnomes are freaking brilliant - avatar elemental people and feywild happy folk
• The section on "bad guy" faiths is so much better than personified gods - malleable ideals can fit more settings and make better stories
• Session 0 Eberron Edition is very much something that should have been in the PHB or DMG - BUT I wished it included some advice on how to prevent new players who don't read much from getting overwhelmed by the astronomical amount of material about Eberron
• Secrets of the Barren Sea and Rierdra open up new campaign settings but with a decidedly different flavors that feel spooky and paranoid
• Astral plane feels very classic DnD but teeming with new hooks and I appreciate the distinction with spelljammer
• Demystifying the Karnathi undead is very thought-provoking
• The Riedra portion alone could be its own mini sourcebook, LOVE that map and the 1984-Matrix feel

Suggestions:

• I want a small map locating each niche nation/culture/city as they're introduced because the Eberron world is very big!
• Similarly art is so important to not only promoting imagination but also explaining - give us more pictures of these places and peoples - what do The Inspired look like, how might we render an every-day scene in Riedra? How about those rock elemental cannon balls? Some of that new metamagic in-action? A map of Ashtakala?
• I'd love a glossary/footnotes and/or summary of terms for things like Marbar or Daelkyr or a history of Xen'drik, perhaps an interactive map with where to read more about whatever region; sometimes I have to visit 3 wiki articles to read just a single paragraph and if I'm away from the internet that's hard
• KB you should pen the Spelljammer and Planescape lore for WotC, you're so much better at it than they are