I can usually get a race and qualifying session in before I need to replace them.
Been thwartd both times I ran them this year, first with a hub failure at VIR and then with a wreck 12 laps or so in at Roebling.
Initial impressions on the R1-S: the "bleed out" of the mold stuff is way worse than Hoosiers. First lap must be gentle.
After that, I'd say same or even better grip, confidence, etc. than the R6. I didn't overheat them at Roebling and I drove them hard. NOt sure about longetivity yet but I will continue the experiment at the SIC, and possibly the ARRC (not sure if the gearing works there with the slow corner onto hte back straight).
I LOVE the R1S but have not run the R1. I run them on my T4 Mustang and they work wonders. Now the Mustang weighs in at 3450 so its quite heavy for the tires too. I can usually get a race and qualifying session in before I need to replace them. Talking with the engineer's from BFG..there is no need to heat cycle them before using. Just scrub them in for about a lap and then go. They hold up really well and are consistant thru a race. If they start getting too hot..you will know it. Back off for about a lap or so and then right back to it.