I have never read one halo book, but I do think that, TECH and The Director have very valid points and that the flood add a hell of a lot more combat dynamic into the game, with the fact that they come back after being killed intitially and that they are essentially the "backbone" of the halo series, being the real threat and the reason for the Halo array and lets not forget the fear factor they add, But I think that for the most part, bungie did a really great job slipping them into the halo series and that they're a very unique "zombie" type enemy.