More accurate? no. Quieter? yes, definatly. And also faster by about 4fps.
Accuracy is dependent on a lot of variables, most important variable being that nut behind the grip. Practice is the best way to improve accuracy. Now back to the question, I don’t see how an STS could affect accuracy unless it wasn’t setup right, like being offset to one side of the string causing it to kick the string to the side.
I put a MeanV CSS (and a Torqueless grip) on my LX and SB. I finally learned how to hold the bow. The CSS eliminated string slap so I don’t need an arm guard. Along with more careful tuning, these things helped my comfort and confidence, thereby allowing my to shoot more accurately. I can’t really give all of the credit to any of these variables, but I am more pleased with my bows and my shooting than in any prior hunting season.