I have both types of then and have run them same day on the bench. I do use a different muffler as the V-60 has to use a strap-on type muffler. Mine both run better for me with 10% or less. I really prefer 5% unless I have a gallon of 10% open that I want to use up. I am a huge fan of the small case ST 60! I do have a really old V-60 that has a baffle linked to the carb ( the carb opens backwards to todays modern versions) that I will play with someday. It may be one of the old one's that can use the higher nitro......