I think the golf ball analogy is a decent one, but it tends to overlook a few factors I suspect are at play.
1) The dimples are all the same with respect to one another
2) The dimples are of a depth and size that you can bet is not accidental
3) The golf ball is a sphere
4) The dimples, while dimply, are very smooth nonetheless. I bet a golf ball that was roughened by sandblasting wouldn't fly as well.
I think port roughness probably helps on cold engines and at lower port velocities, and that's a valid contribution. But at 7,000RPM on a hot engine, I doubt there's much time for the fuel to get any more or less separated from the air.
On my engine I'm putting together, I'll run it on a carb to get it worked out. But then, I'll switch to injection and the injectors are positioned to spray fuel at the valve and into the chamber. I hope it won't matter how rough the ports are. That said, I think a secondary issue will be that the injectors of today don't produce that great of a fog....more like a spray.
