City on Fire: Worth reading this 900-page novel?

I certainly hope that Knopf's incredible investment of $2 million in advance for the first (?) novel by Garth Risk Hallberg, City on Fire, pays off for the renowned publisher (it has for GRH for sure) - I'd like to think that a novel can earn out that much $, but it also seems the investment, though it bought a ton of publicity for this writer and this novel, is a typically idiotic investment: who makes these decisions? I've started reading this massive (900+ pp) novel, am pretty sure I won't finish it - honestly, there are many other books I want to read - but I'll give GRH his props: His writing is sharply observed, witty, clear, and, once you start to get the characters straight in your mind, pretty easy to follow. It's been compared w/ Dickens, though I'm not sure why other than amplitude, but it seems a closer comparison to other Manhattan opi such as the Let the Great World Spin, The Emperor's Children, or even Bonfire of the Vanities: a large cast of peripheral characters, a few central ones, lots of interaction and path-crossing, against background of gritty urban life and social movements and, in the first two cases I cited above, against a background of a major news event. He hits a certain trifecta, which I'm sure helped build the hype and the advance: writing about the generation of publishers and editors in their youth (the late 70s), about hip urban youth of a certain era viewed in hindsight w/ romance and pathos (it's about several young people in nyc in the 70s, which a nice look-back in the brief opening sequence), and of course it's about New York - would a similar novel set in Chicago or St. Louis have drawn a $2-million advance? Are you serious? I am no doubt one who from time to time enjoys settling into a long and complex novel, but from the first 50 pp or so I'm not convinced that the game is worth the candle here. I'm impressed w/ the writing moment by moment but only vaguely interested in or invested in the characters. I'm not in this world, I'm just a passer-by for the moment.