Actually, that's a pretty good assessment of the books, although, for some reason, I get the feeling I liked it a lot more than you did.
Zelazny was pretty big on duality - not good vs. evil but more of order vs. chaos, energy vs. entropy, and that sort of thing, and he usually chose individual characters to express (or, more accurately, champion) his ideas. Hence, his dispassionate description of the army scenes, as opposed to his vivid descriptions of duels and one on one scenes.
He was also heavily into mythology, which he incorporated into several of his books - Hindu mythology (Lord of Light), Egyptian mythology (Creatures of Light and Darkness) and Scandinavian mythology (The Mask of Loki). Out of those, I consider Lord of Light his best work, and one of the best standalone fantasy books I ever read - although it just might have something to do with my personal preferences, such as grey characters, mythology background, and clever schemes - oh yeah, and some kick-ass duels. I did mention the duels, didn't I?