Personally I think the music for the Prestige isn't much to write about, but I think the soundtrack was purposefully written that way because I think it was meant to supplement the visuals and not be anymore overt. So I think the music remains to be the brooding atmospheric kind.
When I first listened to the soundtrack, I didn't watch the movie and I thought it was really bland. But after I saw the movie, I started to enjoy the soundtrack more, primarily because it reminds me of the images of the movie. Just my two cents.
I think his score has a good presence actually on screen and compliments the film very well, but truth is I consider it more of a mood piece as opposed to a score you can listen to on its own. I think it works as something to accompany the film more than anything.