I've only had R1Rs for a couple weeks. I bought them from a guy who used them for 2 years for autocross (after having them shaved to 4/32nds). In about 20-30 events he wore them down to 2/32nds and the wear is a little strange. He wore one of the tires slightly more than the others due to spinning the rear wheel with his open diff. But with track miles or normal street miles it would be a non-issue. It also depends on how aggressive your suspension setup is as well.
I wouldn't use the R1Rs as a track tire as they don't really tolerate heat very well. On a cool day, sure they'd be fine but on the other hand, RS-3s like heat and Rivals do well in all temperature ranges if the reports are to be believed. So I'd go with one of those for a track tire for sure. FWIW, the STX class winner this past weekend in Wilmington was on RS-3s against a whole host of cars on Rivals. If it were me though I'd pick the Rivals.
Honestly, the Toyos are only popular for autocross in the 195 size. The way they are made is different when comparing the 195 to a lot of the other common autocross sizes as the sticky rubber goes all the way to the cords with the 195s. That said, with full tread this doesn't matter at all, but once you get down to 2-4/32nds it makes a difference.