About halfway through and by golly it's exciting (even in spite of the huge amount of exposition and what are basically pages full of world-building notes). It's The Hunger Games for geeks. I'm not sure if it would appeal to anyone who didn't grow up as a sad nerd, er, I mean, person of specialized interests, though. It also strikes me as being a YA or teen book yet only adults would really appreciate all the 80s nostalgia, so a bit of a dichotomy (which doesn't seem to have done its sales any harm). I like the occasional YA book though, that youthful, aspirational energy makes a nice change from the decaying, withered husks of despair we become as adults.
Anyway, iz gud buk (so far).
I hear monsieur Spielberg is making it into a "moving picture" to be released next year (2018) so it will probably be everywhere then.