Fastflight1. From the little info you put in your topic i would say it would will not make much of a difference for you.
I want to sugest something else. (not saying it would be THE thing for you)
See how many strands there are in your string.
I think you can easyly go down to 14 strands and this will increase your speed alot faster than those balls.
I believe the more you hang in your string, the slower it will go.
And after reading about damage to cables....mmmmm.....i would not even think about it...
Good luck.