Well in the SE region, they often put all the GTS cars with us in the Blitz group, at least thats been the trend so far this year. The MA race I just did, they put GTS1-2 with Lightning, and the faster cars in Thunder. I figured that I might want to switch tires to really be serious about competing, but the RRs dont seem to be that far off some of the other known sticky tires other than the softest of the bunch (Hoosier A6s etc).
I just registered, they also just added an entries list page and we already have 4 registered including myself.