Can you elaborate on this? The skill description says it uses two weapons, but when I hit the training dummy, the damage seems to only correspond to what would happen with one weapon. I’m testing this only very casually, using random stuff I equipped on a low level character designed for another purpose, but when I have one weapon equipped, I hit for 150-200 or so on a cadence hit and I get the same result, only once overall, not once for each weapon, while dual wielding.
This leads me to believe in two possible outcomes. Either cadence does not actually use both weapons, in spite of the skill description, intentionally or otherwise. Or it does, but the game doesn’t display the damage properly. That seems unlikely, though, because while casually smacking enemies with either one or two weapons equipped, the enemies don’t seem to take more damage on the prime cadence hit while dual wielding than with one weapon. I admit I could be wrong on this point, however, since it’s hard to measure and I didn’t test very carefully.
Second, does dual wielding actually make you attack faster for the purpose of Cadence? Of course it does overall, but since cadence doesn’t count the dual attacks from dual wield, is there an overall advantage? Does dual wield apply an overall attack speed increase to your attacks aside from the chance to attack twice? Again, testing casually with a stop watch and measuring by closing my eyes and listening for the special sound of a cadence hit, I noticed that with one weapon or two, the cadence hit typically came every 1.5 seconds. I did not control by using two weapons of exact same speed, but I did notice that while dual wielding, my measurements erred slightly under 1.5 seconds, whereas they were slightly over with one weapon. I expect that’s explained by my error of using a faster off-hand while dual wielding, but I could be wrong.
Another argument I’ve heard for why cadence is good with dual wield is that multi-hit WPS skills count each hit. That’s not true according to my tests, they only count as one swing.
At any rate, my experience just swinging at the dummy is that the prime cadence hit gains nothing from dual wield in terms of frequency or power. The huge amount of flat damage gained from deadly momentum might make it worth it anyway, however.