I have my Babolat Y-105 laced up with the stuff, at 47 lbs. Mains, 45 lbs. crosses. I have heard that the great sap back i can feel, will go "flat" somehow, someday, after repeated flex's. i haven't ever used anything like this and I sure hope my playing 3 times or so a week, won't need a restring anytime soon. What are the bigger brains thought on the subject?