I began playing with wood rackets in the early 70's and reached a 4.5 level. Now entertaining the idea of returning to tennis after twenty years, I tried the k-factor 90 Tour and loved it. It seems perfect for those who played with wood racquets and developed a classic style. But I am constantly told this stick is only for players in tip top condition, which is not my case. For which specific reasons should I be concerned about using the k-factor 90 Tour?