I spent a good portion of my range time last summer working up a load for a 1908 Mannlicher Schoenaur. Just shy of 300 rounds down range, I always got the better group using the DST. But that's just my one experience and I'm no fantastic rifle shot for sure! Perhaps a better un-set pull would have given different results.
I must say that my experience doesn't in any way compare to the number of rounds fired and the numerous different firearms used by JDS. I can see how the transfer of motion in the set mechanism can disturb the aim. As small and fast moving as the set parts are, they are in motion just before the shot is fired. The set trigger hitting the sear knock off just an instant before the shot is fired has to disturb the aim in some small amount. If your heart beat can be seen in the cross hairs of a 'scope of a closely held rifle, I have no doubt the set mechanism going off disturbs it as well.
But I still like 'em!
