I'll admit, I bought this book mostly because it was highly unlikely I'd be able to borrow it from any friends, with the general rarity of its player base. However, I was a bit more pleased than I had thought I would be. The gameplay mechanics make it play almost like a medieval "Hunter: The Reckoning", right down to the monster-hunting theme and virtue-based powers (in fact, many of the Inquisitors' special abilities are even renamed versions of Hunter edges, for better or for worse). They also sport "Holy Arts", spell-like abilities which seem rather ill-defined from each group's other basic supernatural powers (perhaps they were meant to be a bit more cross-sect?). The book is fairly light on mechanics and rules, but heavy on history and backstory, which is a big help for storytelling chronicles that deal with such immense, complex, and weighty issues such as medieval religion, church and state. Another interesting diversion from Hunter's premise is the idea of curses for each sect of Inquisitor, divine punishments that come from pushing their limits or just as a supernatural balance for their powers and a definite source of humbling. These vary from group to group, but all of them are creative and very interesting. The Inquisitors are a distinct step above Hunters in power, in spite of all the parallels between them, but the careful balances of virtue, vice, power, humility, and those troublesome divine curses all keep things in check. The playing field into which the characters are thrust is one I've always considered both dark and beautiful; Namely, the world of ancient religion. Clashes of faith and man against man can potentially become even greater and more important themes than demon-hunting, if you're inclined to that sort of storytelling.
All in all, though the sorts of characters are just a tiny bit limited, this is a surprisingly worthwhile book. You could even work it into some interesting crossover. Try explaining these as the medieval versions of the Hunters, more in-tune with the divine entity that empowers them or just shaped by the consensus of the times. Or for some real sadistic fun, throw some of these bad-boys in amidst a group of Society of Leopold hunters in a modern Vampire: The Masquerade game, and watch your players scramble for cover and try to figure out what the dickens just took apart two of their coterie mates.