However, you shouldn't try tuning with the knock sensor; all you get is an ignition map that won't knock. This is not necessarily the same thing as a map tuned for best power.

I don't strictly disagree with that. But if you don't have the time/money/preparation to tune, it's nice to know you can drive around without knocking until you can make it to a dyno.

True enough. I'd set the spark map to be conservative enough to try to avoid setting off the knock sensor, however.

For now I'm going to use the PNP map, I don't know how "on the edge" it is, atleast in the atmospheric part of the map. But once I go turbo I guess a trip to the dyno is inevitable.

Not very - we backed it away from the edge for obvious reasons. :)