I went out for a good ride to get a better feel for the G852.
I can say for sure, it is a stiffer sidewall than the metzler, no doubt in my mind now.
Lateral grip, no abnormal behavior observed.
Straight line grip, slight chirps at high loads while accelerating, didnt seem any worse off than the metz.
Turn in, slightly better, high speed sweepers actually felt identical to me.
Feeling the tire with hand after a 100mph sweeper pushed to "just" before peg dragging, it did seem quite warm, warmer than the metz got, but also softer, so I suspect it is a tire that will do fine until pushed hard for an extended period where overheating will cause rapid degradation.
Makes sense since its OEM on a bike a little lighter, with less lean angle capability, and about 40% less power.