I love the IPrestige Mid which I recently bought, but I can tell it is sensitive to the string and tension. Right now it is strung with OG micro 17 at 50lbs. I feel the string is too stiff for this string. Since I'm not familiar with strings in general, what would be a good string for this racket which is 18x20 and 93sq.in. ? What about Technifibre E-matrix, Prince Sweet Perfection, or Iso-speed Professional (I did a bit of research) ?