Plenty of differences between the two guides... you should probably own both. I do and refer to both of them equally. The Official U.S..... guide is commonly referred to on the boards as the C&W guide after the authors. Color pictures, contains states/areas other than just Nevada, and very well done. The disadvantage of this book is that it doesn't include LE's...mainly just house chips and roulettes. It also hasn't been updated since 2008... The Chip Rack (commonly referred to as TCR on the boards) is much more complete for Nevada chips. You will rarely find a chip from Vegas, Tahoe, etc. not in this guide. And it is udated frequently with new editions coming out about every 6 weeks (kidding ). TCR uses letters to describe the value of chips..... A-Z. A is $1-$3 if I remember right. Z is $800+. On the bottom of every page, it gives you the legand of what $ value is associated with each letter. It makes it convenient when you look up a chip and see a U value for example..... you can quickly look at the bottom of the page and see the value of U.

The important thing to remember....is that they are just GUIDES. Do not consider the prices quoted as the end-all-be-all value of a chip.

Hope this helps