My company has dabbled with the fixed versus Optimum Flap for A330/340 fleet for some time. Tail strike avoidance was one reason given by the fixed flap fans. At the end of the day, it's all just silly really. The manufacturer wouldn't have called it optimum if it wasn't that. Train your pilots properly and use Optimum Flap. In the 2 yrs since moving back to Opt Flap, we haven't seen any tail strikes, or increased tire failures for that matter.