Well I'm playing on pc so I don't have dawnguard, also the base damage depeonds on what perks you use in one-hand tree. I do like the bow and daedric dagger, I don't duel weirel. So for example is + 60 more damange 30 x 2 worth it? BoW Legendary as of right now does 43 damage, daedric dagger 41 or I think 39 I have to re-check.
But with the daedric dagger I can start leveling enchanting and adding perks into it so I can get 2 enchantments on it.
With enchanting the daedric is going to give you more total damage output, espescially with double enchanting once you get there. I have two DB daggers I switch between, one does 35 fire damage and has a pretty tolerable charge, the other does 35 fire and 35 frost. That on top of the base damage far outperforms BoW. The same will apply for daedric. BoW looks pretty cool though.