I just bought 3 of these frame,
Frame 1 - Yonex Pro Poly tour 57/55 (1.20)
Frame 2 - Yonex Pro Poly Tour 55/52 (1.20)
Frame 3 - Spiky Shark 55/52 (1.25)
I tried 2 and 4 grams of lead at 12'o clock with Frame 1 and 2, I took the lead off after 5 min. it was terrible, I was hitting everything long (no control).
I then tried 2 and 4 grams at 2 and 10. A little better, but I still dint think I needed it. So I took it off, this racquet just needs the right string at the right tension and after that you just need to hit with confidence. If you like to hit the ball early this frame will do all the work for you, you have to have good footwork.
I am a 5.0 shb, i grew up on clay so my natural game is to hit heave top spin and move the opponent around, waiting for anything short to flatten out and follow it in. I can serve around 110 mph and the kick serve had tons of spin on it. I am switching from the Bio 200 lite (I feel I maxed out on what this frame has to offer), so the switch.