the response just controls the amount of fuel that is immediately injected; so you may get a little jerkiness from running too rich off idle if you turn it too high
in general though, it seems to be best to turn the response as high as possible without getting the jerkiness off idle; you get a little quicker "response" to your gas pedal pushing -- it seems to me anyways
unless you have upgraded injectors, the gain and idle should be at 12:00 unless you are sure of your A/F ratios at all RPM's
Setting the gain at 10a means you are leaning out the whole mixture AT ALL RPM's by 4%. If you have an A/F gauge & EGT gauges and you are running rich, then you can lean out your gain some. However, if you are not running rich, and you lean it out, you can blow your engine. So I wouldn't do it unless I was sure. It is better to be on the safe side.
