I've been finding that rigs sound consistently better by setting it to -0.5, just curious what others are doing. I also set high shift to -0.1, those settings together seem to make the KPA sound much more natural through my DXR10. Of course, this could be specific to this particular speaker (probably is).
BTW I had set the clean sense on most of my rigs to -6dB for a while, where the input LED barely lits yellow with my main guitar, but since I've always had a feeling that there's a "right" setting for this control, when it changed from absolute numbers to dBs in recent firmware updates I couldn't resist trying it at 0dB, and you know what, even though the input LED blinks red some times, I feel it gives me more useable dynamic range.
Now I've been through lots of different approachs to making the KPA sound its best, and some times what happens is it seems to sound better just because it's different from what I was used to hearing before, the never ending quest for novelty applies here to a certain degree. Maybe a better way to be sure a change of settings actually sounds better is measuring how much time is spent noodling with rigs after making the change. So far it seems promising