Dear Ken,
I've looked at this several times in the last week and have tried to search my soul for a response.
I generally do not screw with the stereo width seperately from my panning set-up (which does indeed feature some things panned hard left and right) but, you know, there's really no reason why you shouldn't. Sounds like you're onto something good. You are aware that pushing the "sides" up has the effect of bringing the lead (in the center, I assume) down while leaving it's efx hot.
As Al Schmidt has often said, "I just turn knobs until it sounds right."
George
