The two balls have two completely different cores,the SSS has the rotary core,the RSX has the rotary 2 core with a wrap,the RSX the wrap lowers the RG. I would imagine that the two balls have quite a difference in ball reaction,but that depends on what you want the ball for and how it's drilled,and how you throw it.Check out the specs and pics very close of the two and also take a look at the Retro Resurrection to see the difference the wrap makes. Hope this helps.