Recently bought this apacs racket- Armor Flex F-10 Power. It was designed in the way that at the middle of the shaft, an over shape tube was replaced instead of the standard "O" tube. Top and bottom shaft - 'O' tube Middle shaft - overshape tube Have not really tried out the racket...do you think this kinda design will increase its flexibilty, swiftness and power? Will input my review once I try it out this thursday nite. Cheers.