Overall I really enjoyed this book, and I am going to start taking a lot from it. Many things need to be house ruled and buffed. But I do have several issues with this book.
1. Minor typos and inconsistencies, Death Drinker is called Lingering Blood in the spell Blood calling. Empty body is called Freedom of Spirit in the Ascetic descriptions. It also needs to specify information in more places, it tells you about blood pools and points in every single chapter taking up a large paragraph, but I still cannot rapidly find any information I am seeking, and have to bounce from chapter to chapter.
2.They seem to be scared of making the classes and races in this book too powerful. The Revenant has 8 weaknesses, no ability bonuses, cannot go one day without feeding without class levels from this book, and the only thing they get is immunities to poison and disease and a +4 vs mind affecting. The classes get very few permanent bonuses instead getting many activated abilities. Blood points also seem a little scant, even if you captured every single enemy that had blood worth drinking it would be unlikely to recharge enough points to offset the cost of downing those enemies. And if you go on any sort of longer trek you will begin to rapidly notice the lack of blood, which helps with characterization and the like, and I did really like the magic item that stores blood.
3.Instead of rehashing the monk I would instead of made it so it focused on powerful strikes instead of a lot of strikes. I would prefer the ascetic was more the vampire who overcomes his weaknesses and made his temporary bonuses more permanent. Make it so maybe he doesn't get any blood powers and instead gets stat bonuses.
4. I wish they had a section more for NPCs and how to really incorporate them into the world, maybe expound upon the clan system to be more like Vampire: The masquerade. They also should have avoided naming specific people and organizations when they don't have any relevance in most campaigns.
What I really like is how sunlight affects Revenants, it may be a little harsh and I would consider making 3 stage necrosis instead of 2, based on duration exposed to sun. I very much like the idea of losing weaknesses as they level up, But I would prefer they didn't have as many to start with, and they got the sunlight feats instead as they leveled up.
I like how they create new ways for individuals to become a vampire, but I dislike how many ways there are. I dislike how easy it is to become a revenant in some ways and hard it is other ways. In the Revenant section all you need is to do a ritual to nocturne and 100g and you have an 85% chance, or you need to take 7 levels of a prestige class, but with that prestige class you become more of the vampire from the bestiary.
I do like how you can take all sorts of feats to make your vampire more interesting and the blood powers all seem very vampiry, I did like how they balanced them all nicely. Although I dislike needing a feat to learn 7th level blood powers, and having that feat insta-kill you in sunlight.
They never explained aging or death in anyway, as far as I could find. I would prefer them to be a little more immortal than they are presented in this book, going into a hibernation/torpor from lack of blood instead of being instantly destroyed by necrosis after 2 days. They also never explained if you die at -10 or not, but I seem to recall reading something about chopping off the head and anointing it with holy water. But it is very hard to find the specific information in this book.
Either way I take what is there and modify it.
My Ideas: Make it so Revenants don't naturally heal, and give them all an ability that heals x amount of hit points by using blood from their blood pool. I would make the Revenant blood pool increase by HD, in addition to class levels. I would even consider making the blood pool a skill that ranks can be put in, so a Revenant could be a core class or something similar. I also think they should have vulnerability to Fire damage, as vampires are known to have in other media.
I would make them more flexible and less rigid, especially the Ascetic because seriously if I want a vampire monk he will just be a vampire with monk class levels. I honestly think the Revenant warrior is the only one worth playing. I think they need a sort of rogue-talent choice they can make at individual levels to give them some bonuses.
But it is an amazing book, that does something that I cannot find anywhere else. I will be taking a lot from it, and it is free, so it is an amazing value. I really love the feats and blood powers and will build on those. I would pay for a version that first fixed the typos and inconsistencies, had very well designed classes, and considered the possibility of characters not wanting to play the classes in this book.
I will be adding a lot of my own content to this book in my own personal notes, this book deserves popularity, because it is a gem. If there was a larger demand for this kind of book it could be improved and remade, and I would buy it. I already wish there was a forum or wiki somewhere with everyone's take on improving upon it and homebrew classes and the like.