Would be great to have both classes on the same tire.
Don't really like the idea of an open tire as everyone will be trying to find what is a couple tenths faster, and some will get there sooner. Eventually most will be running just one tire, and some on the pointy end will be running a different tire for each track, but that prep level is inevitable regardless of tire rules.
I only have 1 track other than Mid-Ohio that I've ran the RR's, (they sucked at Mid-Oh new), and they were pretty good there (Putnam Park), but seemed to fall off after the 7th or 8th heat cycle. Now, these tires may still be good on other surfaces for a few more cycles, just not enough data collected so far to really tell.
Initial tests on a PTE / E3 1.6 Miata (btw, not mine) of the RR had a single set running up to 8hrs in three enduros (2 @ Buttonwillow & Sonoma) and many many warm-up, Qualifying & sprint races at these same tracks (I estimate 9 to 12 'sprint' cycles). We utilized multiple experienced drivers (again, not me), times did not fluctuate very much and there was no complaints of them 'dropping off'. All we did was flip them on the wheels, rotate from corner to corner and store them in black plastic bags. As Hille says it may be 'a track thing', but in Cali with proper maintenance I've not seen big drop off in times.
Once again from my biased position I feel it necessary to point out the NASA remained with the RA-1 while the RR was being developed for our use. NASA SM had a very active hand in developing the tire with myself and Rob Bougoon involved at the first tire test (three different constructions with the current RA-1 & RR compound). By design, the RR should have more grip that the RA-1 (construction differences) with just as good life (same compound as RA-1) and won't need shaving - which is exactly what everyone I asked wanted in a tire at that time.
Now folks are complaining about rain tires - 'eff me!
IMO the RA-1 is a perfect rain tire where smart drivers finish and smart drivers with car control and big onions podium. A 'proper' wet weather race tire, just like a grippy dry takes a portion of the driver out of the equation. Plus for us it will be spec tire so if it sucks it does for everyone. I like the fact with a shave'able tire I can have full depth (long life / heavy rain) or shaved down for intermediates, so we can have degrees of sucky'ness. Fun, I tell ya. Fun!
NASA will not go for open tires in SM, it's not good for the class so that ain't gonna happen on my watch. BTW, anyone want a job? You want to run open tires, go play in PT class.