I finally got around to reading all of The Lost Heart of Asia by Colin Thubron. It was written nearly 15 years ago shortly after the breakup of the Soviet Union and is still one of the few books of this type that cover all 5 Central Asian countries.
There were certainly many parts of this book that I enjoyed. It was fun to follow Thubron around Central Asia as he visited many places I'd love to see. He usually didn't skimp on describing people and places. He did describe too many drunken feasts though (those get old quickly, and I got tired of those descriptions about 5 years ago).
But this book really is very out of date. It was republished after September 11th but really has absolutely nothing to do with Afghanistan or terrorism. Central Asia is a very different place now and this book falls more into the category of history that current events.
He visited Kyrgyzstan last and he seems to have gotten tired by then. All references throughout the book to the Kyrgyz depict them as basically being oafs. Here's the cream of that crop describing the Kyrgyz he saw in Bishkek:
They lumbered along the streets as if breasting mountains, and would drop unthinking to their haunches on the pavements. Their mastiff necks rolled into barrel chests. Their hair was cropped into a utilitarian black bush, beneath which the jowled, brachycephalic heads belonged in Mongolia...Their rolling-pin arms swung out from muscle-bound shoulders, and their felt hats lent them a doltish gaiety.
He does say they are more refined Kyrgyz, but personally, I've never seen people who match this description in any part of the country, whether they've been in Bishkek all their lives on never set foot in the city. So I don't recommend this book if you want to learn about Kyrgyzstan. It's strongest on Uzbekistan, then Turkmenistan. Kazakhstan's chapter is nearly as short as Kyrgyzstan's, but he seems to think the Kazakhs have a bit more potential than the Kyrgyz.