I was thinking about single hits, but yeah, the super slam does more if you get both hits. Though it's still 45 for the strong hit.
It's no secret that Horn is great in multiplayer, but I was specifically talking about its damage output problems (which is very relevant to me since I couldn't really go online, so I had to solo pretty much everything). Speedruns are indicative of a weapon's damage output in both speed and ease of positioning, which HH has trouble with in some fights due to awkward swing angles.
If I get the opportunity to go online when I do get XX, I'll go back to fiddling with the HH a bit, but I'm not really sure since the Maqam Sedition's songs are still ass, and that was my favourite thing.