I have use the M11 HEAT 600 for a few hours. Strung with BG66 at 25lbs. Vibration to the hand during games is very low. The feeling is very driect. Hard swing smash is powerful. Counter-smash return even better , replusion off-center of sweet spot is as strong as center contact. racket is well-balance. Like very much it for double play. Currently, i am also using 1) Apacs Lethal 7- speedy defensive return, whoosh slicing sound during smashing 2) Impact Super Power 8- Head heavy racket, hard smashing specialist 3) RSL scream 098 - Balance, likely it for double play. but lost to HEAT 600 in all department except value 5 times cheaper for the frame. 4) RSL scream 088 - light, not powerful , vibration is moderate. bUDGETRACKET 5) RSL scream 0166 - stiffess racket among all the scream series. Conclusion: if budget is no issue, i strongly recomend M11 HEAT 600 over yonex arc-saber z-slasher. for value.