I know how these threads can form endless flame wars until someone locks them and I don't want that to happen. So I'll look at this in another perspective.
Consider this: We don't know how to measure each one's power. Hell, the only Dante we can try to measure it's power is SMT one and even he is very debatable on that. I mean come on, he never even "dies". DmC at least implies half-demon breeds can be killed; but in DMC, Dante dies twice! Or maybe even three times if you'd count the fight at the beginning of DMC4.
And even if we could measure any of that we still don't know how to implement devil trigger or even the devil arms into this. We have no way to be sure.
But in my opinion they are roughly around the same strength. I don't see any of them dominating the other one. It would be a very close fight and the outcome would depend on both the environment and their physical/mental state before the fight.