In a few hours I am about to hit with the 4 Pro Kennex racquets TW sent to me to demo. I was not pleased to see 2 of them strung with Wilson NXT, one strung with "Non sensitive test string" (?), and the last with a white string with no markings. When I last demoed racquets from you guys (in '02) I thought the policy was to string all lines with the same string at 2 lbs over midpoint. Today I will be hitting with different racquets BUT will the difference in feel be because of the frame or also partly because of the string? I just HOPE they are all strung at mid (or mid + 2) or else who knows what I will be reacting to with different strings, different relative tension and different frames. Please comment.