I've been playing in and running Gaslight setting for the past four years. When this book was originally announced, I got extremely excited hoping that Chaosium would bring to the table a book of quality to equal the 1920s Sourcebook. Well, we didn't quite get that.
+Interesting new traits system that can randomly blight or boon your investigators (or just be funny).
+Great information source on the time period is more flushed out than previous edition.
+Illustrations and photos throughout add to the feel of the setting.
+A "bestiary" of famous fictional/historical figures of the period is included, though while not very useful is humorous.
+The book's historical information is of course very useful. Concise and fun to read as well as giving the keeper the basics of what they need to know. The map is especially useful.
-Same old occupations. Really? I was very hopeful for a volume of occupations similar to the 1920s Sourcebook, but instead we're left with the same dozen and a half or so occupations. They even actually removed the Street Arab occupation from the book.
-No extensive equipment or weapons list. I didn't expect there to be a list nearly as extensive as the monograph on the subject (Gaslight Equipment Catalogue, Monograph #0319) but I was expecting a little more than what is given.
-Another Sherlock Holmes campaign. I didn't read through it as at the time of this book release I was already in the middle of an epic two year long campaign (switching over to this edition of Gaslight about halfway through). I find the idea overplayed though.
Overall this is a good book, great for bringing a new generation of Gaslight gamers around. However, if you have an older edition already I don't feel like you're missing anything by not buying this. Just a side note, this book was released at least six months after its original announced release period. After making me wait half a year past when I was expecting it the book fell short of my excitement.