I have a set of Super Lights and yes the compound is harder than the mudlites. Also they have a wheel guard to protect the shiny wheels from rocks.

The tires have an overlap that looks like a lip and it protects the wheels from getting scratched at the corners.Hey Sweet tooth....What do you mean by a wheel guard...Is that just side wall tread? The extra tread to stick out to protect the rims? Hmmmmmm