Im considering restringing my racket using the rsl turbo nano strings. There r two types of strings tn660 power n tn680 ultimate. My current strings is bg66 um about to end it current services very2 soon. Can anyone share their experience and info about these 2 strings comparing to bg66 um or nbg 98 which both have good balance in control and power. Im stringing my racket at 26 n 27lbs. Other alternatives strings suggestion (except yonex strings) will be much appreciated.