This review contains spoilers.
I thought I'd got a remaindered, 1000 page, hardback book, from a prominent author, at an absolute bargain price because the publisher made a typo on the cover. Unfortunately, that typo is deliberate. It was made by one of the characters in the book and gets propagated widely in malware.
I read this book to the end so that I could provide a fair review for SoylentNews but I really wish that I hadn't. At around the 75% mark, I wanted to abandon the book. Around the 95% mark, I was more interested in my bookmark than the book itself. The problem is that the book is too detailed and yet not detailed enough. The plot flips from a semi-autobiographical character to a dodgy Scottish accountant for the Russian Mafia to a needlessly exotic Black, Welsh, lesser-known contemporary of Osama bin Laden. Internal motive is rarely explained and therefore Welsh's Islamic subjugation of another needlessly exotic character makes her seem like a really irritating Mary Sue when it should have been a highly researched study of cultural belief.
Until reading What ISIS Really Wants, I thought the book would have benefited highly from Mary Sue being killed in the first half. Either way, it may be beneficial to read this book while referring to an atlas. It certainly seems to be written that way.
Other reviews note the comic relief. This made me think "What comic relief?" Then I remembered the rivalry between a snob and a hack who provide a superfluous backstory for an inconsistent online game which adds very little to the plot. The snob, when he is able, has his email translated into a language of his own devising, written onto vellum and delivered on a velvet cushion. Unfortunately, Right Ho, Jeeves by P.G. Wodehouse (published in 1934) has superior observations about telecommunications and doesn't explain its Noodle Incident in full.
One seemingly outrageous section of the book involves a siege and building collapse. However, subsequent events in Paris made this a case of life imitating art. Unfortunately, this occurs in one of a series of exotic locations reminiscent of a James Bond film. (Quantum of Solace springs to mind but SPECTRE also fits.)
The plot isn't resolved in a satisfactory manner and an epilog doesn't help. Every bad guy dies. Every good guy lives. A character with dubious morals receives an injury which forces reform. What happens to the mafia guys? Who cares because it was just a device to get to the jihadists.
Three people are credited in the book as providing expertise for ships, guns and geography. Unfortunately, due to the repetition of "gunwales", "clip" and "talus", and the lack of editing thereof, it seems more like Neal Stephenson collected on three bets. This is the overall problem with the work. Light editing of a literary great has destroyed the value. Applying a firmer process between author and editor would have been far more beneficial.
Neal Stephenson's early novel, Zodiac, is preferable to REAMDE and this is generally regarded as inferior to Snow Crash, The Diamond Age and Cryptonomicon. On this basis, REAMDE is probably the worst Neal Stephenson novel ever published. Publishers, William Morrow and Atlantic Books, should be ashamed.
I think that Snow Crash should come before Diamond Age, but just my opinion...
I see that you don't mention the Baroque Cycle [wikipedia.org] which I think is his best work ever, barring Snow Crash.