When the first string trackers came out, we had a box of spools to play with that was supplied. We found that they were quite limiting for taking cross wind shots past 20 yards if there was anything close to the arrow travel line for the string to snag on, be it a twig or a weed. Maybe they are better now. My turkey heads are four blade HERTERS, a few guys use bludgeons for turkeys. One of those has gotten a number of turkey, the last time I talked to him, he said he was still using them for turkeys. With my shorter draw and slower arrow speed, I think I will stick to the Herters. My hunting tactics are too variable to run around with the strings. And even though it is a bit embarrassing, to quote John Schulz, "that second arrow and the ability to get it out of the quiver and onto the string will pay off in bowhunting." Nope, I did not get a second shot at the ones I missed, but twice, the slower and not to quick on the draw buddy that was tagging along got nailed with the Herters. No time to tie up a second arrow in those cases. So far, I have not had a turkey that I hit go very far.