The pros generally seem to string their APDs with this string in the low 50's. But that's what they like. The only way you can determine what tension you like is to try the string at various tensions. Just don't start off at 60# unless you're a ranked Jr or a really strong player. Your best attempt will probably be in the low 50's initially. As far as gauge, thicker will last longer than thin, so the 16 Ga will last longer than the 17 Ga. Also depending on your style of swing/grip, you may get just as much spin from the 16 as the 17 Ga. But generally, the 17 Ga will bite the ball better. How long they last will depend on your hitting style. There is a BIG HOWEVER; this poly plays really well for about 4-5 hours after break in; then it falls off a cliff.