I lived in germany for a while and have been to a lot of motorcycle museums...don't remember if I watched that video though as I never really cared about 2-strokes.Liked the book the Nazi-TT !
I always love to play with KTM's.Of course in a straight line the 1290 is faster but in the twisties and especially on bumpy pavement I have never encountered a rider that was "Ready to Race"...

The GS always won...

Of course on the track I ride the S1000RR as the GS has no chance or business being there but you can still have fun with a GS on the track if you know it's limitations;ground clearance,tires that can stand the heat if you are fast enough and of course only 125hp while heavy and aerodynamic as a barn-door...

But if you are a good rider you can still embarrass some lesser riding-gods on real sportsbikes with your GS which is always fun...

There is a reason the No.1 bike in the alpes is the GS.There is no faster bike in this environment and a KTM being a bike from the alps too has no chance against a GS despite being superior on paper and "Ready to Race"...Trust me !
Only bike that would be better would be a slightly lighter GS with 17 inch wheels with more TORQUE to steer into fire out of the turns even quicker as you don't utilize 8000 rpm or 125 hp in the alps very often,or better very seldom !
The GS-Rally was the best bike for the alps last year and is it again at this years Alpen-Masters for a reason !