Sens manual 24-30, 167 silvers, 150+ IH's, from nothing but pounded parks Aug-Dec.
If we are looking for a single best setup forget it, its not going to happen in my opinion.
For a while now when I have found a signal, I have been testing that signal with both my normal high sens setting, a lower sens settings, a lower gain setting, and semi-auto. This is the only valid test in my opinion, same signal, same ground, same day.
Semi-auto...I don't trust it at all, I have seen too many signals vanish altogether or become extremely iffy. Even good signals degrade to some degree. They are not robust if that makes sense. In your area this may not be a problem, semi-auto may be the ideal setup but come to my parks and you will miss targets running 32-auto.
Can the sens be too high? Yes for thick green coins, yes and no for silver. The higher the sens on the green ones the more they try to sound like iron, again this may not be true in your area. Back off the sens and the higher coin sounds return. Silver on the other hand just seems to sound better the higher the sens goes.
But wait, with the sens cranked up high if you are getting a fair amount of faint high falses you will walk right by those faint silver signals, you just can't pick them out from the chatter. On the other hand I have tested silver signals that were iffy at sens 28, that were barely a bleep at 24, and gone altogether at 22.
Gain is another tricky one, I love 7 but if I'm getting too many high faint falses I'll miss some faint silver. I have been throttling back to 6 of late with better results but still run 7 when conditions allow, even 8.
I'm coming to the conclusion that if you really want to extract ALL the good targets, you need to pound it 2-3 times with different setups. Even different sized coils.