String follow is supposed to be smoother, with a small loss of arrow speed, while backset is supposed to give a bit more speed with the tradeoff being a bit of handshock or harshness. I own both, and I don't notice a huge difference between them. Maybe I am too club fisted to feel the variance. All my bows are in the 55 pound range, and they all shoot to the same place at hunting distances with the same arrows. The SF does seem to arc a bit more at longer ranges, however. Since I don't plan on taking 40 or 50 yard shots at animals, the difference between them is of little consequence to me.