Even though the "Shadows of..." books are now, in the game timeline, five years out of date, they still provide excellent background information for Shadowrunners to use to flesh out their characters.
"Shadows of Asia" is a good resource for those 'runners coming from -- you guessed it -- Asia, providing the history of things to come for every major country in the Middle East, India, China, Japan, Russia, and southeast Asia. With so many different countries presented, though, certain sections seemed like they skimped a bit -- there's very little on some of the smaller nations like Vietnam, whereas the Japan section is huge. China's numerous small nations have individually little information presented for each, but on the whole, the China section is actually longer than it looks. Likewise, the section on the Middle East isn't very long. Russia is presented here and not in "Shadows of Europe," which is something to remember for those who want to run characters from the wrong side of the Iron Curtain.
One disappointment of mine was the lack of information on Australia, New Zealand, and the Pacific Rim; no information at all is given about the ANZAC, its surrounding islands, or Hawaii.
Overall though, it is worthwhile. It gives players a good idea of the Asian shadows as well as the usual assortment of redrawn maps in case your next run takes you to the PacRim. As usual, there are dozens of little hints and off-hand comments throughout to provide GMs with ideas for plot hooks and shadowruns.