I'm going to write my review without biasing myself by reading the others.
I lived and worked in Siberian and the Russian Far East for several years in the 1990s. Frazier has always been one of my favorite authors; he is king of detail. "On the Rez" was a phenomenal book. Missing my second home, Russia, I snatched up Travels in Siberia the instant it became available.
I'm going to start with the limitations of this book:
1. East of Chita and Yakutia, the locals uniformly call their land the "Russian Far East." They do not call it Siberia, any more than people from Idaho or California call their land the Midwest. Just like Americans have the Midwest and the West, the Russians have the corresponding landlocked Siberia and the coastal Far East. It perpetuates Westerners' geographic misnaming of the region.
2. Leaving the history of Siberia's Indigenous peoples out of the book. This is the most egregious oversight of this book, and it's particularly perplexing given Frazier's history researching and writing "On the Rez." Can you imagine an author writing on the history and the experience of the Dakotas without mentioning the Sioux? This book manages to paint Siberia and the Russian Far East as the historic battleground of Russians and the Mongols, without mentioning the couple dozen tribes - of Asian, Turkish, or European descent - that migrated to, lived in, and defined Siberia for centuries before either the Russians or the Mongols arrived. In a few of these regions, Indigenous peoples still outnumber Russians, and it is still common to hear the native languages spoken on the streets or in government offices. Frazier writes about two visits to the Republic of Buryatia without clarifying that Buryatians are Indigenous descendents of the Mongols. He then visits a bit with the Even peoples in Yakutia, but again fails to relate any information about their history, although the book has some history on the Russian colonization of the region.
3. Frazier entered Siberia with the notion that it is All About Gulags; that is a typical American lens/misperception. Siberia is a whole lot of things, and Siberians do not, nor did they ever, think of their land as Prison Land, any more than Californians currently obsess about Japanese internment camps in California. In both places the gulags are a sad and horrible history but they are far from defining the place. If you lived in Siberia for a year and listened to Russian conversation, you would never know there are any prisons there. Another stereotype of Siberia that Frazier failed to question, and ended up just perpetuating.
4. Siberia and the Far East are the very most beautiful (a) in nature and all the wilderness parks, which Frazier never seems to get off the highway to see!; and (b) in private homes, where Russians and other natives fully open their hearts and are your best friends for life. Frazier is more exposed to the (much harsher) "public life" of Russia, the train toilets and the public litter, than to its wonderful private life. Russians often said to me, "I've visited America, and it's boring there." What they often mean is that Russians, and particularly those who live east of the Urals, are a very social, hospitable, warm, fun people who know how to have a good time. Frazier for whatever reason barely gets a peak at this. And he writes about forests, but never really gets a look at how gorgeous they are in Siberia, because he is always sort of on the main drag, pushed on by two hosts from St. Petersburg who only want to drive faster rather than slowing down and actually seeing anything.
That said, this book is wonderfully written, has riveting detail, and has some truly brilliant insights into both the Russian psyche and the land that Frazier visited. Worth reading.