I like gut in crosses but at the 4 hour mark they begin to fray. Will Tonic gut be quite as good as VS as a cross string with poly as a main? Will Tonic be more durable than VS considering the lesser quality of Tonic? If Tonic is an alternative, should I go for the 15 or 16 gauge considering feel and durability? Remember gut willbe the cross string. I hit with heavy topspin on both sides and slice a lot also wih the backhand.