I've played with my ArcSaber 11 now for a couple of sessions and I've been surprised by the amount of adjustment required from my Arc10. In my opinion the Arc11 is significantly stiffer than the 10. Head weight is basically the same I think. The racket seems a bit more stable on reaction shots but for some reason clears and drives are requiring a bit more wrist strength. The power is there when I strike it cleanly but this seems to be a much more challenging racket to use than the Arc10. Which is odd because my experience seems counter to all the reviews I've read. My Arc10 is quite old now and maybe the shafts loosened up over time or something? The Arc11 has potential but I'd recommend people try it out first if possible.