After owning about 20 Schafer's since 1988, I now prefer the fast-flight compatible models! And I never thought I would!
I had my first fastflight model built in 2007 while I was struggling with shoulder issues and target panic. I had the bow built at 56 lbs draw rather than the 70 I usually shot. I wanted to gain some umph I felt I was losing by dropping more than 15 lbs in draw weight. I also requested Dave use lamboo cores as I had heard they were somewhat faster.
When I got the bow, I put on an SBD D97 skinny string. First thing I noticed was how quiet the bow was. I only needed one set of cat whiskers per end rather than the two I had routinely used with Dacron to get the bow whisper quiet. With the brace height the same, I started tuning for arrows and found the exact same I had shot with my 70 lb bows flew flawlessly out of the 56 lber. I bare shaft tune my bows and these arrows were perfectly straight in flight and hit in the same group as fletched arrows! Same spine, same point weight, same everything! To me, that implies the same force is being exacted on the arrow from each of the bows shot…a Dacron bow at 70 lbs vs a FF bow at 56 lbs!!
Now I can’t say for sure it was simply the FF string, the fact the string was skinny, the lamboo cores or less weight from the catwhisker set-up. More than likely it is a combination of all four. But because of these findings, I would prefer fastflight for all new Schafer’s I get in the future!!