Tian Xia has always been
Tian Xia has always been the part of Golarion I've found the most interesting, particularly the prominence of a variety of non-human peoples that have real political weight and influence on the continent where they are often auxiliary elements in societies elsewhere. There's plenty of beauty, drama and horror to be found here; nagaji hermit kingdoms, esoteric philosophies, Tengu clans forced to unite under the persistent threat of thalassic invasion by a Kraken tyrant, Gang managed Gokan Street Fighter arcades, fumeiyoshi courting freedom fighters in the murder-casino that is Chu Ye, and so on. This is a great book that goes into all sorts of the diverse and sometimes surprising topics from the other side of Golarion and I'm excited to see what Paizo, DMs and players can make of it.