I wouldn't mix and match different brands and different compound tires on a performance car but that's just me. Mixing new and old of the same brand and same compound tire is okay to me though (front vs rear).
I have a base C8 and it's not too bad. It performs fairly well and gets a lot of attention. I haven't driven the Supra so I can't really compare, but I'm sure the Supra holds its ground in its own way.