Shigure IV question

I have a -Spd IV shigure, and want to know if I should use Desp or Vantage? He is +HP, so not the best IVs, but its what i got.
With Harmonic Lance+ for Speed, he still has 37 speed. It makes sense to use his natural A-slot skill and Vantage to be a enemy phase unit, but his speed is still high enough to use Desp as well. Thoughts?