I recently fought Havelock on my low chaos playthrough, and the music was so cool, also the killcam was brilliant.You stab him in the arm, grab his gun and make him shoot himself, all whilst this epic battle music is playing. http://www.youtube.com/watch?v=bH7ylc2tGac is an example of the scene. One of my favourite moments of the game. Wish the battle was harder (it's literally a case of slashing him three or four times) but hey, the music and the killcam more than make up for it.

yeah in certain instances the music was so killer! I wish they release the ost for the game soon

Well, Havelock isn't really any stronger than a normal guard I would think. He just has a higher rank.