Honestly I hated it. It was like the author realized the battle for the Hork-Bajir valley was only going to take 70 pages and they needed something to help fill it up, and oh, a late-night airing of Glory on TBS. Perfect.
Plus, I don't want to start a fight but I read some really uncomfortable implications into the whole comparison...like if the blacks were supposed to be compared to the Hork-Bajir, does that mean they're big, stupid brutes who are actually loving and peaceful deep down? Idk, I haven't read the book in a while but I remember getting that feeling near the beginning and getting really icked out, but the parallels were muddled a little bit by the middle/end of the book, mostly with the introduction of the sci-fi nerds that died or whatever, which made it less allegorical and more, I don't know, counterpunctual I guess. But...short answer, I hated 47.