I'd say, hands down the best of the V20 line so far, and I honestly can not wait until Lore of the Bloodlines, (which I wanted even more) to finally come out.
A consistent complaint I've had about the V20 line was that it didn't feel like Vampire the Masquerade as much as someone's rewriting the game to get their home campaign ideas, (some of which are just bad) into canon, or something along those lines, even if it meant removing things from past editions. The V20 lines has also lost that defining spark that made me fall in love with Vampire the Masquerade, and in truth tends to make reading those books somewhat dull, (Ghouls, Black Hand, I'm looking at you). While this is all still somewhat true here, it's very clearly to a lesser extent all around.
Instead, Lore reminds me a lot of both versions of the old Clan Books, except all in one place. When I first started off reading it, chapter by chapter, I actually told someone "It felt like reading an old VtM book, once again", and I meant it. After I'd gotten into it more and more, I started havign some doubts, some are just better than others, though to be fair, this has always been the case, and some degree of personal bias may also come into play, making it difficult to tell if which I honestly liked or not, but I didn't walk away disliking the take or "reimagining" they had gone with this time.
I've never been a fan of the Assamites or Tremere, and still really am not, but both are very good chapters here, and I really like the idea that most of the Tremere chapter is taken from the out of game stance of "yah, we know it doesn't make sense but it's a Clan, they did survive, and here they are" and the unreliable narrator works perfectly.
Each chapter is filled with options, ideas, mechanics, and the like, though it's NOT restricted to just that Clan, which is a big plus.
Unlike the V20 main book, this one has time to go into some more detail rather than just present options, and they use that space well. I highly recommend this book, and if anything else in the V20 line is closer to this than the direction they have been going, I'm more excited. Especially if Lore of the Bloodlines is even close to this.