Because I'm somewhat lazy, I'm just going to toss my thoughts up in this thread. Maybe I'll combine them into a proper review later. I'll post one chapter at a time (as I'm doing this as I read through the book, and I have a lot of other things to get to tonight).
Introduction
This section introduces the Celestial River pantheon and explains what the authors intend to do with the rest of the book. Fairly straightforward. I'm ambivalent about the Celestial River pantheon at this point. The text suggests classes and races that may worship certain gods, and, this is purely personal feeling, I think it would be stronger if it didn't, as then characters would worship certain gods based on personal views and thoughts rather than "I'm a halfling, and most halflings worship Kulaj." Of course, others might find that sort of certainty more useful for their campaign. No worries. One side note, the text says that only Mallock "is not neutral on the good/evil axis," which is not true--Urgan is neutral good (I'd probably make him true neutral, if I wanted to stay within what the text suggests).
Chapter I: The Oracle of Jezer-At
This chapter deals with the oracle itself and the gods Enaul and Essoch. The Oracle itself, aside from being a resource for characters searching for information, has real effects on divination spells cast (increasing caster level, range, and altering other effects in interesting ways). There's a short section dealing with the priests of the Oracle (which are not necessarily all clerics, as all members of the organization are called priests). I felt that the writing in this little section got off the rails a bit; the passage felt repetitive as I read it (this cropped up--the writing feeling awkward--a couple other times in the course of the reading, but I'd be hard-pressed to give specific examples, and it doesn't interfere at all with the content, so.... Mind you, the overall quality of the writing is excellent; I might be being picky, as I've been grading papers a lot recently).
After examining the potential for intrigue at the Oracle, we get descriptions of Enaul and Essoch and two sample characters (a priest of Enaul and a diviner working for Essoch). There's also a sidebar detailing costs of service at the Oracle. This all looked fine to me.
The next four pages deal mostly with how to adjudicate and use signs/visions/omens/portents and all that in your campaign. This is more advice for a DM than for a player (and a fairly sharp departure from the first BoHM, which seemed mostly aimed at players). The advice is good, and there's a handy list of general and specific phantasmagorias (with meanings) that could be wicked helpful to the DM working with this stuff.
The rest of the chapter is filled with crunchier stuff (a skill, feats, domains, spells, and items). These are my thoughts on the matter in the order that they came to me.
- Profession (Speaker of Portents), although very specific, feels funny to me (I can't imagine a character choosing that as a profession). I'd probably call it Profession (Oracle) or something like that. As for it as a skill, I'm not sure it's necessary, as I feel that it gives mechanics to something that I'd probably want not to have them. That said, I can see it allowing a player to play an oracle without needing to be hyperactively smart or observant.
- The feats are fine and appropriate. I really like the Craft Charm Set/charm set deal and could use it in my next campaign. Seer would be really useful for a diviner, but I can't see a lot of players taking it in place of other feats. I'm pretty ambivalent about Vatic Sight, although I like the idea.
- The Civilization domain power seems weak (a +2 circumstance bonus to Gather Information checks made in a settlement over 100 people). I'd at least bump it up to +3 (as Skill Focus) and would consider having Gather Information become a class skill. The scope seems almost too narrow to be useful on top of the low modifier.
- The spells: I love Aid from the Future (wicked neat and evocative, IMO), Commune with the City, and Precognitive Flashes. I like the other spells, too. I'm just a divination fan, I guess.
- Items: the charm sets, which are cantrip-activated minor magic items, could be useful in a low magic game as an alternative to potions or something to use with potions. The sample charms are pretty basic, but have some neat flavor text (for example, the personality charm set consists of "two cloth pouches filled with rose petals and powdered rhino horn, a strap of cloth rubbed with sea salt and bearing three circular gold charms, and a broken dagger hilt"--on one level, this seems arbitrary, but the components could be changed pretty easily, I'm sure). The artifacts (Crook of Essoch and the Hourglass of Enaul) don't do much for me, but I rarely use/think of using artifacts in my game, so that's likely just a predisposition of mine.
So far, so good; I'm really liking it. I'll post more later.
Best,
Nick