ORIGINAL: davepjr71
The drop away rests are more accurate for people with shooting form flaws and/or bows not tuned properly. By loosing contact as quickly as possible there is a less likely hood of a hand twist or a quick squeeze affecting the shot.
Spring steel rest provide guidance for form flaws and are more forgiving because of the guidance they provide,that is why the pros use them.They use every LITTLE adavantage they can because the difference in 1 shot might be the difference in 1st and 10th.
To understand this,watch all the slow motion video you can findof what an arrow does when shot.The arrow is not stiff when shot,it is moving (absorbing energy from bow)and a rest that is guiding that arrow,the more it will want to go where aimed,the spring steel rest does this WHILE stll being soft and not forcing the arrow out of it's naturall oscilation.
A prong rest does much of the same but clearance is more of an issue and spring tension is crucial to maintain some of the softness.
I like fallaways,especially for hunting because of the clearance on helical fletching and the containment you can get with them but that is really the only advantage.