I recently have owned and played both of these I found the 569 to be much more stable and really long for me the SIX seemed to be loose my SS is right at 100 and my tempo is quick, I will say however , the friend
of mine who bought the SIX swings slightly slower and smoother hits bombs with that shaft , matching the shaft to you is the key I also think both of these shafts require some tipping work to really dial them in, my 569 is tipped 3/4. good luck