From what I recall, Blue’s are a slightly more aggressive compound, with shorter life than HT10’s (but I may have mixed those up). It also depends a lot on car weight and intended track use (Do you plan on doing something like Mid Ohio/Watkins Glen/Mosport or Dunnville/Cayuga) Both are a good choice, it really comes down to personal preferance once you have them spec’d out. I’d suggest starting with a lesser compound and moving up. The more agressive, the more heat they need, and at dunnville you arent heating them up THAT much.