I love Heidnau tires for their great performance on wet dirt roads and much superior performance in the dirt in general.
They last a long time on paved roads too. as long or longer than most dual purpose gs tires....ie hard long lasting rubber!
I have a real hard time in saying they are "great" in the twisties too!
The only measure of a tires performance is at the limits of it's traction!
these Heidenaus have a much more knobby /open tread vs the normal gs tire. because of this open tread the actual rubber contact patch could easliy be 30% less rubber on the pavement. ie less rubber on the pavement ...less traction!
On top of this most would agree that Heidenau long lasting rubber is harder for long milage...but therefore, sill less traction.10% less, 20% less???
summing these together it would seem that the Heidenau 40% or 50% less traction on dry pavement.
the means much longer stopping distance under hard braking..aat the edge of abs limits.
It also means in the twisties the tire will lose grip and you will low side much sooner than on normal dual sport tires.
It also means that traction on wet paved roads will be poorer too when at the limits.
If you are riding twisties at 4 or 5 tenths then you are ok, but if some one cranks it up to 8tenths...don't try to follow on Heidenaus.