Also keep in mind that - SoloNSX, correct me if I'm wrong about this - Solo competition rules usually require street tires. I've heard that many such events define street tires as those carrying specified treadwear ratings (e.g. 200 or higher). So an "extreme performance" tire like the RE71R or the ZII Star Spec (both of which have 200 treadwear ratings) might be allowed, but an R compound track tire like the Nitto NT01 or Toyo RA-1 (both with 100 treadwear ratings) might not be permitted. If OTOH you're not in actual Solo competition, and you have enough track experience to take advantage of the greater grip offered by an R compound tire, you might be better off with that than with one of these street tires. Different tires for different folks, depending on how you're using them (street/track vs track only, solo competition rules vs HPDE events, etc).