All scrubbed in and I note the tyres roll very smooth. They turn nicely too, in fact I'm quite impressed. Dead stable and here I am going around roundabouts and I scrape a foot, which is surprising as I don't usually. normal suspension settings and years of riding racers sees me 'step back' onto the ball of my inside foot for each corner. I have run them at 2.5bar and 2.9bar and find that they are quite hard, so I'm guessing at a similar wall construction as other tyres that have the same load rating for the GS, so I dropped them to stock reccomended settings, with a little extra at the rear, so back to 2.2bar front and 2.6bar rear. very very nice and still roll very well. grip is much better at this pressure and I am happy.
I had the opportunity to drop off the side of the road onto gravel at 90kmh (literally ride off the edge, to avoid a mobile chicane) and they set up well, and were stable enough to drop back onto the asphalt, a step up of about an inch or two. on the gravel I was able to turn the bike quite well, but a decent ride on gravel will let me know about whether they work as well as other 90/10 tyres.
so far, so good.
ps. punctures suck, rear got a small puncture on day one, but no structural damage or belt damage, so prof. repaired.