I've seen Reamde described as Stephenson's most accessible book, and I suspect that this is true. It wasn't at all what I was expecting, since the last time I noticed what Stephenson was up to, he was putting together some vast sprawling web-thing which involved Mongolia.
Rather than being the fruit of that labour, Reamde is a comparatively straightforward - for him - thriller set pretty much in the recognisable present day. It's a fun read, but it's not really what the fans were probably waiting for. To understand why that's a bad thing, we have to do a bit of a survey of the work to date. We will stipulate that all Stephenson books are far too long and full of digressions.
His first big hit was Snow Crash, which is probably the shortest book he's done since hitting the big time. It's a wonderful sprawling mess of larger than life characters in a dystopian not too distant future. It races through ideas and preposterous situations so fast that it's not immediately apparent that it doesn't really make a huge amount of sense, and it doesn't really matter that it's all over the place because it's tremendous fun (where to start; the hero is called Hiro Protagonist; the Mafia is now the biggest economic force in America, but it only delivers pizza....)
The next book was the more focused but somehow madder The Diamond Age, which had a world warped by zero cost nanotechnology and China as a new economic superpower operating on whimsically Confucian lines (well, I just checked Wikipedia since it's almost 20 years since I read the book, and I've got that wrong, but never mind). In and among completely re-imagining political economy for a world without nation states or much need for money, it also contains a feature complete attempt to explain Turing Machines and a riot of other stuff. I ought to read it again, but there's a stack of other stuff I have to do first.
Then comes Cryptonomicon, which is a 900 page doorstep that jumps around WWII and the present day with a wildly complicated plot about cryptography. It ends on a sort of cliff hanger which left most readers waiting for a whole bunch more material about the Waterhouse and Shaftoe families who provide most of the main characters. We're still waiting....
Because that would have been too easy - Stephenson then took five years or so to chunk out three absolute monsters generally referred to as the Baroque cycle that take more than 2000 pages to give us the 17th century ancestors of the Shaftoes and Waterhouses. It's a great mad romp which makes less narrative sense than anything which had gone before, but was full of distracting detail and colourful incidents (it includes, for no particularly good reason, a duel fought between some minor characters with howitzers).
Then came Anathem, possibly his most weirdly ambitious book to date, and the first one he wrote to be set on an entirely imaginary world; all his earlier work was either set in recognisable history or a plausible future of our own bad little habits gone mad. Anathem was, naturally, long and discursive. It takes forever to get started, and then kicks into shockingly high gear. It is quite difficult to give a terse summary of all the new stuff in it, but it's full of ideas which no-one else has ever written down before, sometimes for good reason. It's also weirdly GOOD; it's sensibly focused for once on a single character and he has a very satisfying resolution of his adventures.
With Reamde, Stephenson sticks to the idea of a long a book which is all over the place, but there are very few new ideas in it. Instead, incident after incident gets thrown at the reader until the only option is to suspend disbelief and wait to see who's still alive at the end of it. I think there are at least a dozen viewpoint characters of importance. The breakneck nature of the incidents is probably best summed up with the moment where the most important character pauses in the middle of an emergency to wonder if anyone else in history had ever been attacked by gangsters, jihadists AND bears in the space of a week. In a way, it's story telling by hyperactive five year olds. One character makes a deal with a front man for Russian gangsters; this goes wrong and drags them into contact with first the Russian gangsters and then Chinese hackers and THEN Welsh jihadists. It's all strung together by coincidences, and sometimes you'd be forgiven for thinking that Stephenson's decided to do an entire series of adventure novels all in one fat book and just get the thing out of his system.
It's fun, mind you, and full of those little Stephenson touches which always make him worth the trouble. No-one has ever quite equalled him in describing a particular kind of modern male mindset; the guy who knows how to something precise and technical, but not how to figure out what other people are thinking. Working entirely in the present day, he can shine a light on all kinds of little corners of that mind. It's just that there are no great big ideas to go with it. Stephenson seemed to be taking a day off from making up cool stuff. Of course, he's already made up more cool stuff than anyone's got a right to expect....