I recently had a demo of the Kzen, and thought it was a great racket. It felt as though it was arm friendly. It's stiffness rating is stated as 71. This kind of makes me want to stay away from the racket for fear of long term effects. I had TE in the past, but all healed now. If anyone can provide me with there feedback regarding playing with this racket on a regular basis it would be greatly appreciated. I am also thinking that just looking at the stiffness rating of a racket might not be the right way to judge if it is arm friendly or not ?