This is the first city book for Mage, and set in the Revised time frame.
The book has chantries and the statistics of NPCs there. Vegas has a lot more mages by the numbers but most are left for the ST to define-though there's some of every major faction listed.
There's background on the various casinos in Vegas, general happenings and history, and other material so you can start a chronicle-pretty standard White Wolf fare. There's also rotes and a sample adventure which are neither exceptionally good nor bad.
The main issue is that this book presumes the Ascension War is over and conflict is minimal. The Technocracy and Traditions are a bit too cozy and you would think that in a city where great fortunes are won and lost every night there might be more power plays between mages.