Well I'm currently using feather professional blades in my feather DX. I've had around 20 shaves. The first 3 shaves are too sharp and harsh then after that the sharpness is about right. Only blades I've tried.
I suppose I want smoother and bit softer than the AC pros.
I think I'll stick with the diamond spray 0.5 micron for now since it comes with the paddle. Can always buy some CO later I suppose.