Buster,
If you are indeed running at Autobahn speeds of 100-130 mph and seeing bulk oil temps of 240F-270F, the 0w-40 is going to give you a bit better protection - specifically from bearing wear. The old 0w-40 Tri-synthetic had a high temp/high shear viscosity of 3.6 Cp, so that's about 15% higher than their 10w-30 supersyn stuff.
The HT/HS viscosity correlates pretty well to bearing viscosity - in fact that's the reason for doing the test at a high shear rate and temp.
If you were doing heavy towing at low speeds, you might want to go to a 0w-40/5w-40/10w-40. Running at 70-80 mph actually doesn't load the engine much at all, so a 0w-30/5w-30/10w-30 synthetic is fine.