This book certainly fills a gap, because from my own history programs growing up, I remained unaware of Asia's and Africa's history unless and until it interacted with European or American history.
Journey has sections for each country/continent. So for example, you get Vietnam's geography, people, everyday life (subdivided into city life, country life, recreation, education, religion, and health care), government, culture (subdivided into arts, theater, music, literature, fashion, food and drink), wildlife, economy (subdivided into agriculture, forestry and fishing, mineral and energy resources, manufacturing, services, transportation, and communication), and history. I certainly benefited, especially from the history sections. I appreciated the evenhandedness of the descriptions of the religions, including my own.
Did my kids benefit? I'm divided. While each chapter was very thorough, none of it besides the narrative histories was related in a memorable way. Often even as I was reading aloud, a sentence that perfunctorily listed its facts would appear, like, "Other important rivers include the Indus, Brahmaputra, Narmada, Tapi, Godavari, Krishna, and Mahanadi." And I'd think, "Why am I wasting my breath here?" Honestly, unless (and possibly even if) you're willing to drag out a map, what purpose does the sentence even have other than perhaps to check a box? No book we've read so far for homeschool has reminded me so much of the textbooks I grew up reading in public school. A "living book" this is not. In other words, it is boring.
Still, I think it was valuable for my kids to march through a book that isn't fun but contains good info, to be repeatedly exposed to words like "economy" and "agriculture," and to get a 30,000 foot view of other cultures. I think it helps them have a wider set of categories. It was extremely handy to be reading literature set in each area as we went, so that I could pause and relate it to something from Journey. It's hard to say whether I'll do it with my son when he comes of age. I may just use the histories--and have all the other sections for a reference.