What, so my reply of "There is no perfect setting, it's all down to the individual" wasn't obvious enough for you? Look, if you want to go by the Nissan book spec then Alex's post gives you all you need to know, and if you want to go for something out of those specs for trackwork then you'll simply have to do what everyone else does and that's experiment. My setup could be far too oversteery for you and you'd hate it, and it just as easily could have far too much understeer for your taste. It's a personal preference, and it's the reason that performance car manufacturers set their cars up for maximum oversteerability before they give them to Clarkson to test, as that's how he likes his cars setup and will give that car a better review because of it. They'll simply set it back to 'normal' specs before the car goes on sale.
How much under/oversteer do you want on the car? Or do you simply want it neutral? Nissan spec will be slightly understeery to help keep the n00bs on the road so slightly more aggressive than that will give you a neutral car, but I prefer mine to be slightly oversteery for a more defined (and bum clenching if you get it wrong!) drive. Each to their own.