This worked for Snow Crash - felt like I went on a theme park ride, got to the end of it, and hopped off still buzzing. Doesn't work so well for something less tongue in cheek.
Strong agree. I was especially disappointed because it felt like he was dropping breadcrumbs all through the book and then... Nah, none of that foreshadowing mattered. The central tension of the book is handled by an off-screen deus ex machina, actually, everybody go home.