the gold valves have a much greater flow area for the compression shim stack. set up nicely they take all the harshness out of the high speed compression while still giving good control overall. usually you go heavier on springs too.

the std showa oil is nominally 7.5wt. running 5 wt helps with the harshness. you could try 2.5 if you wanted too. maybe then start winding in the adjusters to get the control/damping back into the shim stacks and out of the bleeds, where it's meant to be.