As far as performance, they're pretty equal. If we define performance as stabilization. The shield cut has a bit more drag which is what stabilizes the arrow, but really......It's not enough to notice. They both perform very, very well.

So it really comes down to what you want. If you don't mind that little bit of extra noise, and I can tell you that's really a moot point, and like the looks of the shield cut.....Go for it. If you want the stabilization characteristics of feathers, but want them as quiet as possible, go with parabolic on an offset, not helical. You won't get as much spin, but they will be quieter and a tad faster.

Oh, maybe something else to consider is your shooting distance. Feathers slow down rapidly after about 45 yards, and shields are even worse. I shoot alot at 60 and 70 yards, and I can tell you that my shields on a helical drop off really quick past that. Really, really quick. But, they hit where I'm aiming.