Intake & Exhaust Port Surface Finish.
As long as the intake port surface finish is fine enough so that the highest protrusions are not above the air /fuel mixture boundary layer thickness, then improvements on the finish will have little effect on air / fuel mixture flow . A rougher finish is actually an advantage. Do not over polish an intake port because of its wet fuel flow capability.
A polished exhaust port will increase the exhaust gas flow and will reduce the potential for carbon to build up on the exhaust port surface.
In conclusion 97% of a performance gain from porting a cylinder head is from the shape of the ports and only 3% is from a polished finish.