Brass, Blood and Steam is a useful product, especially given its very economical price point.
If you are playing FATE or Spirit of the Century based games, BB&S gives you guidelines for "steampunking" character skills, stunts and aspects, new character concepts, and some quick pick stunt packages to speed up character generation.
No matter what system you are using, BB&S gives you an overview of the Steampunk genre with lots of books, movies and other games to pull ideas from; important tropes to consider in your Steampunk game such as Lost Worlds, Spiritualism, and the role of Women in Victorian culture; and lists of equipment that are current, cutting edge, or futuristic in the Steampunk Era.
Finally, Brass, Blood and Steam presents a sample Sreampunk campaign outline, based in an Antarctic Lost World, as well as an introductory adventure.
Bad points, in brief, are occasional editorial errors - mostly multiple or free floating articles - and some subjects that feel like they could be expanded upon in some length. Mere quibbles in the face of this product's good point.
Overall, I feel this is an excellent value for its price, and a worthwhile purchase for any fan of FATE games or anyone wanting to run a Steampunk RPG with any rules system.