I have the OS 46 AX on my sig something extra and I run a 11-6 prop on it.

I beleive the smaller size props will make it faster once it's in the air and the larger size props will give you less speed but better pulling power.

On take offs smaller props = longer runway to get it airborne.

Larger props = shorter runway to lift off.

I beleive the more rpm's you get out of an engine = more wear on your engine.

Experiment with different props and then you will know.

If I had the pulse I'd run a 11-6 on it with the os 46 ax.