Although I have not thrown the SSP I do own the RS1 and 2 RSX's . From talking with Roger at Roto Grip the RS1 was designed to replace the SSP. I like it on the right conditions but I believe I still prefer the RSX as it will handle a little more oil and is a little more versitle. I actually would recommend both. Especially for the price, you get high price hit at a midline price. I believe one of the main differences you will see is the SSP was designed for dry to medium where the RS1 is for Medium, I believe it has a stronger move at the break-point. Good luck.
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Todd Loy