Ok,,,,
If you get one that gives improved low end performance, you will normally lose top end speed.
If you get one that increases top end speed, you will normally lose bottom end (out of the hole) performance.
So, unless you do something to increase what the engine can do, keep the stock pitch.
That said,,, Skat will generally give a bit of out of the hole performance, increased across the band performance, and at the very least keep the top end and in some cases improve it. They do this by how the blades are bent and designed.
So in my opinion, go with OEM (assuming no engine performance changes), and or a Skat.