I am a 3.5 player who is currently using a 320g Wilson K90. Besides playing tennis, I also do some lifting. As I get better in timing and gain more strength, I feel that I can handle a heavier racket. My couch said that I should use the heaviest racket that I can handle which will give me more control and penentration. He recommended the Strung Weight: 12.5 ounces: Wilson K90 (9pt head light) or the Strung Weight: 12.8oz: Wilson K88 (6pt head light). My questions: 1: Is it ture that a player should use the heaviest racket? 2: If so, should he add lead tape to increase weight or just go with a heavier racket? Thanks.