The major difference in bow string material is the amount of stretch. Some bowstrings stretch more than others.
Here are the 3 effects of bow string stretch.
Speed of the arrow
The smoothness of the shot (hand vibration)
The noise of the shot
B55 bow strings stretch the most. This means you can expect a smooth shooting bowstring that is quiet. The tradeoff is that it tends to be 5 fps slower than a d-97 string and 10 fps slower than Fast-Flight string. B55 strings are most commonly used for archers who care more about smoothness than speed. B55 strings are also the top choice for people who make their own bows. The B-55 bow string is the most forgiving string, and if your top priority is quietness and smoothness this is the string for you. Click HERE to see B-55 bow strings.
D-97 bow strings are the best of both worlds. They stretch more than Fast Flight but less than B55. You will get a fast arrow and a smooth release when you shoot a D-97 bow string. The trade-off is that you don't get the quietest string or the fastest string but it is a good middle ground and rivals B55 for the most popular bow string. Click HERE to see D-97 bow Strings.
652 Spectra (Fast Flight) bow strings stretch the least. This means you can expect a super fast arrow. The trade-off is that there's more noise on release and possibly more hand vibration. Tournament archers and competition archers often choose fast flight as their primary bow string. When speed is your highest priority Fast Flight is your bowstring. Click HERE to see Fast Flight bow strings.