Not to sound too much like a pimp...
But lighter is not always better. A too light wheel will flex, making it inconsistant. It can also break at the worst possible time. Not to mention the fact that when there is less available traction, lighter usually means harder to drive, from less induced traction (Faster spool up causing abrupt adhesion loss that is harder to stay on top of, feeling like less traction).
I don't even know if the JC wheels and tires are lighter or heavier, but I do know from experience there are different times when both can be an advantage. I have even added lead tape inside wheels to tune this in extreme cases of low traction.
Just my thoughts....
...Jim
W.E.D.