We've covered this in detail before and it always brings out many opinions. In actuality, the shift point for best acceleration is dictated by which gear/RPM provides the most torque to the wheels at a given road speed. It's a bit more complicated than looking at the power or torque curves (sorry Randal
) You have to look at the torque curve, the gear ratios, and the road speed.
For most high performance cars, the manufacturer will choose gear ratios that take full advantage of the rev range. So almost always, high performance cars will give the best acceleration if the car is run to redline. The numbers prove this out on the Boxster and also agree with what loosecannon has found.
I wouldn't worry much about stage 1 over-revs by hitting the fuel cut-off at redline, that's not damaging to the engine. It's the miss-shift that runs the engine beyond red line that you should and Porsche does care about.