Erilaz: STR+16 DEX+42 Great Sword skill +28 (Accuracy+28 / Attack+28)
vs
Nilas: STR+11 DEX+35 Attack+15 Double Attack+2%
For WS totally, probably for TP too, unless you're fighting weak stuff where the DA+2% would be preferable.
Alas it's no inventory+1 because you'll still want to keep Nilas for Lunge/Swipe
From an offensive perspective, Taeon with good augments stomp both for TP (and beat Nilas easily for WS too, though are pretty close with Erilaz for WS).
Taeon Gloves: STR+9 DEX+35 plus TA+2% from leaf stones, and whatever mix of Acc/Atk from snow (mine are 19/19) and STR/DEX from dusk you have.
Sechs has a decent point about Nilas still having use for Lunge/Swipe though. Taeon can win for that too, but I'm not interested in lugging around another pair with MAB augments just for Lunge (in fact, I don't even have Nilas so I'm fine with the base MAB+7 on Taeon).
And definitely true that if you're using Erilaz for the set bonus or resist, that's a consideration. They're both offensively very good and useful defensively. Though you still might want to use Umuthi for PDT-4% depending on your set and the situation.