Now that I had some time to really digest these books, I thought I would post a more critical review. For the most part, my earlier impression holds up. For content, volume 1 and 2 are 5 star books. No more praising, lets get critical.
As many have noted, there are type errors, especially on the less known, and niche domains. The most grievious errors I have seen are whole paragraphs cut short. These seem to occur only on the domains where both the history and the domain lord are the same. It appears to be a very bad cut and paste. Regardless, the full text is still available, its just broken in one part.
The next bad part is chronology. Ravenloft in general, doesn't have a rich history, but it does have one. There are two catestrophic events that dramatically changed the domain make-ups. These events are often referenced, expecially in volume 1, but because there is no introductory chapter, certain domain entries can be very confusing, if not contridictory for people not familar with these events.
This is also not all lore, as advertised. The writers did take some liberities. In most cases, its to fill out some lesser domains, or pocket domains. (Some of these weren't even pocket domains, just quest areas from modules.) The most grievious was Blutspur which they relocated to the moon. I suspect this was fan-fiction from the Raptor wiki page, but its not supported in any official lore that I am aware of. From what I can tell, they didn't alter anything that was established lore.
My last comment is more nit-picking, than critical. For some reason, the included the Gothic Earth stuff. They chose to make Gothic Earth a seperate domain, which is not supported in any lore that i know if. Regardless, Gothic Earth was a totally seperate tabletop rpg system, that used some of the basic mechanics from 2e. It was a very different game, using completely different character creation, and combat/magic rules. It was an effort by TSR to compete with Call of Cathulu with a Poe themed setting. It is completely incompatible with 5E rules. I get why they included it for completion, but other than being under the Ravenloft banner, it wasn't DnD anymore than TSR Marvel Heroes was. I personally wish they had just saved these last pages to add entries on important NPCs and monsters that are not domain lords, such as the Weathermays, Richten, Gondegal and the Forlorn Monster. Maybe even add the lore section that made some of the domains so confusing.
Due to some the errors, and missed oppertunity in the final chapter for Gothic Earth, i am reducing my score to a 4/5. Yes, the errors are bad, but not to a point that it ruins any one entry, and the shear amount of info is absolutely staggering. A definite treasure for any Ravenloft DM. This will be a book I use over the official book. Great job!
If the publishers read this, i would strongly recommend the next entry include general lore, a monster manual and NPC backgrounds.
This and the other volume are absolutely amazing. I was following the development of these books closely, but the final product far exceeded expectations. I personally thought i was a super guru when it came to Ravenloft, but was shocked by some of the darklords I have never seen nor heard of before. I am glad they went with these covers though. I didn't like the originals they had picked out. These remind me of the opening scene from the 1980s TV show Tales From the Darkside. The opening to that show scared me more than the show.
I also greatly appreciate the rough semi-black and white paper. This is the exact same style used in the original Ravenloft Box set from the early 90s. Its an unexpected bit of nostalgia. Another nice bit is the appendixes with the extra creatures and magic items. Its not the full Ravenloft Monster Manual, but what's included is more than expected.
Not only does these volumes include all classic Ravenloft Domains, even the niche ones from magazines, but also contains the Ravenloft spin-off Gothic Earth. Another unnessassary surprise.
I ordered both of these books and 1e Dragonlance book and got them all in only 2 days, despite using standard shipping. (Also got a Vampire the Masquerade book I didn't order, but it wasn't charged.)
Volume 1 focuses on the Core domains and the Pocket Domains.
Volume 2 focuses on the Domain Clusters, Islands of Terror and Gothic Earth.
If your looking for a completionist set for Ravenloft, this is it. These two volumes cover almost the entire 2e and 3e setting product line.
These books are the complete deal and worth every penny.
[4 of 5 Stars!]