I thought it would add paid advantage to players, I might add it as a separate category later if this game gets more players.

But for now, when submitting runs you need to state if you used any DLC weapons or mounts, costumes are fine as they are just cosmetic items.

As I don't actually own the DLC yet I can't be sure if the weapons or mounts will actually be advantageous in runs, so if anyone has it please do tell me the weapon and mount stats (with screenshots if possible).

I think the DLC weapons don't add any advantage, because they're basically fancy unique weapons (with maximum of +19 compatibility - yeah, i made some research).

I don't have any DLC yet because, believe or not, the game isn't in Brazilian Playstation Network, my copy was a review copy Koei send to me. (and personally, I only wanna the costumes DLC and the Omega Force 20th Anniversary Live music DLC), weapons and mounts aren't my thing, but I understand the guys who doesn't wanna play the game on chaotic to pick the unique weapons.

DLC matters a LOT. Faster mounts, different, and better Magic Weapons, etc. DLC makes a difference, for sure, no doubt about it.