There's a point, where the subject matter is a discussion of how to present the Sabbat's violent atrocities in the context of the game, and by way of example, the book presents a graphic description of a violent rape. Then, immediately after, this paragraph:
Okay, well that wasn't too graphic, was it? Now, let's take show how can take the same scene and the same action and slap the troupe in the face with the imagery.
And true to its word, the Guide to the Sabbat repeats the rape scene, but with even less sensitivity and discretion.
I was pretty tired of the book by that point, but afterwards, it became a pure battle of wills to complete.
Depicting something isn't the same thing as endorsing it, and I'm sure that White Wolf was no more in favor of (redacted) (seriously, those examples were super gross) than they were of murdering people and bathing in their blood to celebrate a promotion. But I'm honestly not sure what point they were aiming at.
Camarilla vampires are your supernatural romance vampires. They stand around in penthouses, swirling blood in a snifter, staring moodily out the window, contemplating how they are monsters who are incapable of love. In your various fanfictions, you can replace them with billionaires with very little loss of coherence.
Sabbat vampires are your action-horror vampires. They're the sort that sleep 20-to-a-single-boarded-up-church and inspire heroes to improvise crosses out of old newspapers as they run howling through the streets and the only one who has a speaking part has an ironically high-pitched voice and says something like "ollie-ollie-oxen-free." In fanfiction, you can replace them with minorities, if you're a racist who wants to be really on the nose.
In standard Vampire: the Masquerade, the Sabbat has a clearly defined narrative role as vampires who have given up on the temptations of feigned humanity. They're not out there trying to run a business. Instead, they roll into town like Halloween monsters and threaten your PCs while they're trying to run a business. All vampires, by their very nature, are evil, but the Sabbat are evil and bad.
As a conflict, it works. Your tormented anti-hero who agonizes about every drop of blood he takes can look at them and see a mirror of everything he loathes about himself, your cynical villain protagonist can be shocked to learn there are lines even she won't cross, and your completely jaded mastermind can be put out by the inconvenience.
You could get a lot of mileage out of a Storyteller book that focused on the Sabbat as antagonists, giving tips on how to present them (oh, fuck, White Wolf, not like that, what the hell is wrong with you?!), how to build a scenario or a campaign that featured them prominently, how to handle the social issues at the table (build a time machine and plagiarize from Urban Shadows, because seriously, 90s White Wolf did not have a handle on this, at all).
Guide to the Sabbat, however, decided to go another way with it, centering the book around playing the Sabbat as protagonists. They did not quite succeed at that goal. What they needed to do was come up with an answer for the question "why are you hanging around in abandoned warehouses with, like, 20 other guys when you could be standing in a skyscraper saying things like 'exquisite?'" that's not "because you're a disgusting sadist and Van Helsing should have dusted you years ago."
Ultimately, they went with the only possible explanation - religious fanaticism and nasty blood magic rituals. So, okay, that's fair enough. That's some good villain texture. The Sabbat is one big, slimy ball of unrepentant moral nihilism, but they try to hide that from themselves by pantomiming a religion of moral nihilism.
Where the book goes wrong is when it tries to explore that in a player-facing form of personal psychology. Or, in other words, Paths of Enlightenment are bullshit.
Timeout for a Vampire: the Masquerade rules primer. In the game, you are constantly worried about becoming a monster, and how your terrible deeds are putting you on the slippery slope towards damnation. This is represented by a stat called "Humanity." Every time you do something shitty (and this can be anything from "having an unkind thought" to "serial killer style murder and sadism") you check it against the hierarchy of sins, a ranked list of awful deeds, each associated wit a particular humanity level. If the evil deed is worse than those associated with your current Humanity, you have to check for Humanity loss. If your Humanity is low enough that the deed is less shitty than those at your current position on the hierarchy of sins, then you don't have to do squat - you no longer care about that sort of thing. Eventually, if you commit too many depraved acts, you will drop to Humanity 0 and you will become a mindless, ravening beast.
A Path of Enlightenment is a philosophy that replaces your character's Humanity, substituting a new hierarchy of sins. Whereas the lowest level of Humanity might be "Torture and Extreme Cruelty," the warrior-based Path of Honorable Accord bottoms out at "Breaking Your Word."
The problem with this is that Humanity isn't supposed to be a philosophy, it's supposed to be the game's thesis about what it means to be a functional person. The reason you fall to the Beast when you hurt and kill people is that you loose track of the value of people, and thus of the value of the person-like qualities within yourself. And when those are gone, all that's left is the hunt.
By and large, the Paths of Enlightenment don't contradict that. You follow the Path of Lilith and at rank 2 you get dinged for failing to inflict suffering on someone, but there's nothing there that prevents you from completely objectifying everyone you meet. The Paths can offer a philosophical justification for maintaining low Humanity, but they don't convincingly replace it.
The Sabbat would have been much better served if they'd just owned being low-Humanity assholes. It would have resulted in fewer Sabbat elders, due to rampant monsterfication, but even that fits in with the lore. They could have been sincere about "all vampires being free and equal" instead of hypocritical about it.
Guide to the Sabbat's saving grace is actually Vampire: the Masquerade's overall mushy genre. It's not just a game of personal horror. It's not just a game of supernatural politics and intrigue. It's also a weird sort of pre-apocalyptic, occult conspiracy-driven urban fantasy. There are ancient, godlike vampires who pull the strings behind the setting's various factions and whatever else the Sabbat is, it's also militantly opposed to the Antediluvian vampires.
Because of this, the book is front-loaded with a bunch of High White Wolf folderol. What is a Kiasyd even? They are faerie vampires that glow blue in darkness? Their main thing is that they love to read, and for that reason they are not recommended as player characters? And they're in the book that's otherwise devoted to playing From Dusk Till Dawn-style vampires? Pure bafflement, except in the sense that nothing ever vanishes from White Wolf's canon, it's just gradually metaplotted into obscurity.
Overall, if I had to do it over again, I'd give this book a miss. It has some useful elements. And some offensive elements. But mostly, I've just outgrown the subject matter. Despite the book's use of "mature content" as a euphemism for tasteless gore, abuse, and horror, it's mostly a juvenile exploration of its own underlying themes. It could work for an edgy 90s kid (except that one part, which, for fuck's sake, why), but I'd like to think that now, on the cusp of the 2020s, we have no more need for shock for the sake of shock.
UKSS Contribution - I'm going to go really abstract here and say "vampire eschatology." The idea that vampire religion anticipates an imminent (at least by their immortal standards) crisis that will lead to the end of the world. Not sure what form it will take, but it will drive how Ukss's vampires view their place in the universe.