I very much enjoyed William Dalrymple's "From the Holy Mountain," but this book was a disappointment. It was Dalrymple's first book, and if you consider it as a novice's starting effort and read it with an appropriately moderate level of expectations, you probably won't be disappointed. But the book was overpraised by the British press, and the effusive blurbs on the cover and inside led me to expect something significantly better than what Dalrymple actually produced.
"In Xanadu" recounts a 12,000-mile journey, four-month journey from Jerusalem to Beijing that Dalrymple took in the summer of 1986. That bare description of the trip should alert you to one of the book's main problems. To cover 12,000 miles in the something less than four months of his summer vacation from Cambridge University, Dalrymple had to keep moving at an average clip of 100 miles per day. That wouldn't leave a great deal of time for sight-seeing under any circumstances, but it leaves even less when you're traveling by bus and train in Third World countries where departure schedules are unpredictable and unexpected delays frequent. Indeed, after he crosses the Iranian border on his way east, Dalrymple's account suggests that he spent as much time waiting fruitlessly for transport as he did actually seeing anything of substance in the countries he was passing through.
The first half of the book, which takes you from Jerusalem to central Iran, is far and away the best part, because during this leg of the trip Dalrymple gave himself time to see some things along the way. In particular, he takes the time to relate what he was seeing with what Marco Polo might have seen seven hundred years earlier, which was ostensibly the point of the whole journey.
Then, alas, on page 149, Dalrymple is awoken one morning in Saveh, Iran by his travelling companion Laura, who brusquely informs him that "We're barely halfway to Lahore and I've got to be back in Delhi within the week." This makes it necessary to cover almost 2,500 miles across Iran and Pakistan at a pace of 300+ miles a day. At around this point Marco Polo largely disappears from Dalrymple's account, hardly to return until the very end of the book. On the western China leg of the trip, Dalrymple is foolishly determined to travel through a forbidden zone near the Chinese nuclear testing facility at Lop Nor - supposedly for the sake of following Polo's route - but his passage through this region has to be so rushed and furtive as he attempts to avoid security personnel that it is essentially pointless. In the end, the last two-thirds of Dalrymple's trip sounds like it was an utterly miserable experience, raising the question of why anyone would want to spend 150 pages reliving the experience with him.
It is true (as various of the review blurbs indicate) that Dalrymple is sometimes very funny. But he isn't as consistently funny as is Paul Theroux, for example, and he is whiny and self-pitying at least as often as he is funny. Moreover, over time I got really tired of his disparagement and mocking of many of the locals: he christens one young Pakistani who agreed to drive him and his traveling companion from Quetta to Lahore "Psycho," for example, for no other reason than his breakneck driving habits - but these were apparently necessary to meet the deadlines that Dalrymple's demanding traveling companion had imposed on them.
If you want to read about a cross-Asia trip that followed in the footsteps of Marco Polo, I would instead recommend "Danziger's Travels," by Nicholas Danziger. Danziger did a similar trip a year or two earlier in the mid-1980's, but he took more than a year to do it, and he didn't shy away from traveling through Afghanistan, as Dalyrmple did (albeit understandably). (Danziger's account of the fighting in the ancient caravan city of Herat is particularly vivid.) Or read Dalrymple's account of the Middle East's last Christians in "From the Holy Mountain." Either of those would be a better investment of your reading time than this volume.