I have an R11 TP with a madrix HD6 xflex shaft. When i was trying out drivers last year this baby gave me great numbers. 12.3* launch 2800 rpm backspin and about a 285ish carry. However, I would NOT recommend the r11. After getting it and using it for a little while, i really started disliking the aesthetics. Feels like im hitting a rock, sounds bad and i dont care for the white. That being said, the club performs well, its just not for me. Im back to a more traditional driver in the 910. much better looks, sound, feel, etc. Not quite as long but more workable and lower spin.