Rhu, it's a decent book. It's just that, though - a thesaurus. There's nothing more to it other than words, nothing too fancy about it. But it covers the gamut of fantasy and historical words quite extensively. So if you're looking for a resource to give you more variety verbally, or one that can help you be more descriptive, this will work well.
Personally, I like the
Writer's Complete Fantasy Reference. I ran across this book years ago (10, 15?) in a used book store and it's been pretty awesome. I've used it quite extensively over the years. It's not as extensive in its word variety but what it lack there, it more than makes up for in its descriptions. It goes into detail about its terms and it has many other nifty suggestions. For example:
The Complete Writer's Fantasy Reference, page 11 wrote:marquess (marchioness): Dating from the eleventh century, this title originally applied to lord who were responsible to lords who were responsible for guarding border areas, known as marches.
Or
The Complete Writer's Fantasy Reference, page 15 wrote:deacon (deaconess): Such ordained churchmen, immediately subordinate to priests, were responsible for serving their assistants, in charge of the purification ceremonies connected with preparations for baptism and charged with the care of the poor and unfortunate.
We're old hats at this, so stuff like this might not be as helpful to you or I (though it was for me, truthfully). But it definitely got my creative juices flowing.
It also has other nifty bits. It has a world cultures section - If you want to base a region of your campaign (or there's one that already exists in a published campaign setting) off of Mayan cultures, it talks about the different aspects of their (and other cultures) arts and sciences, government, military, economy, etc. There's a large section about magic. One part I thought really helped me was it presented questions on how to view magic in your world. Are there stories about famous wizards? What's their social status? Are there societies of them secluded away from the rest of the world?
There's a ton more: professions in a medieval/fantasy world by class (lower, middle, upper) and terms with brief descriptions for punishments, races, arms and armor, clothes, castles, and more.
I know you asked about the Storyteller's Thesaurus, Rhu, and I'm sorry I went off about a different book altogether. They actually do two different things, so having both isn't a bad thing. Every time I think about the ST, I'm reminded of the Fantast Reference. I guess I had expectations that the Storyteller's Thesaurus was going to be like the the WCFR and it wasn't, so I found myself going back to the latter book, still, after picking up the Thesaurus. Is the Storyteller's Thesaurus worth the $25? Yes. But if you haven't taken a look at the Writer's Complete Fantasy Reference, it's worth a look, too.
