That said: this book is a not-very-successful Vinge riff. I wish it were a better one. The Zones were a great idea; more people should have been riffing them in the past oh god twenty years; and in fact Reynolds has a nice take on the Zones themselves. The world (rather than the Galaxy) is divided into regions of variable technology, particularly in tiers up the suspiciously beanstalk-like Spearpoint Mountain. (In fact the zones go past "no electronics" to "no machinery" and eventually "no cellular biology, sorry, you probably want to stay the hell out of there." And yes, Reynolds has a good explanation waiting.)
However, the appeal of AFUTD was not the Zones per se, but the sense of a multileveled Galactic civilization and all its attendant wonders. Terminal World wants to portray that -- a vast future world and all its history -- but the scope doesn't stick. It's just a trip, there and back again. A perfectly good adventure trip story, sure, but all the little background details just sit there on painted canvas. Yes, I got the (smartass) hints about the history of the world. They're not worth the effort Reynolds put into them.