Just picked this up today...with two Nyko Perfect Shots. Holy hell, that's fun. I thought I'd have trouble tracking two (or more) independant targets with each hand...but I did pretty well. I'm gonna need to practice some more, though.
Favorite move so far:
Three targets attacking, one on each side, one in the middle. Fire both hands at their respective side, converge in the middle, and then throw both hands out to reload.
And I'm about 100% sure I don't look nearly as cool as I feel while doing so.