Which one is better dps?

In general you can get approximate weapon speed comparisons by doing (10 + speed - booster). So for a speed 6 weapon on an aran, it's (10 + 6 - 3) = 13, vs. (10 + 7 - 3) = 14.

So Arcglaive naturally does 14/13 times as much damage. Which makes the two weapons basically indistinguishable for dps.