Suck it and see!.
There have been numerous reports about blade polishing, sometimes with good, sometimes with poor, results.
It appears that some folk push their blades nearer to optimum lift/drag by polishing them
while some go further away from the optimum.
This probably relates to the individual machine, by weight, blade pitch, and other
variables.
My experience was in this area was a little peculiar.
I roughed up my 23ft extruded rotorhawks with a scotchbrite pad, more to clean them
up than anything.
My RRPM dropped from 360 to 320, with no noticeable performance difference.
I repitched to bring them back to 360. Dreadful performance. Higher takeoff and landing
speeds in particular. So I repitched again back to 320. Back to normal performance.
Since then, it has very slowly crept back up to 360, with no performance change.
My feeling is that I have gone from slightly ahead of, to slightly behind the optimum
L/D, or vice versa.
I suspect the performance variation might not be so noticeable on a more powerful gyro.
If anyone has any opinions on whether 320 is better or worse than 360, I'm listening.
In a rollover I'd prefer 320, in the flare I'd prefer 360.