With the flash tune I have on my X5D now the engine pulls hard all the way to the redline and the "torque dip" is non existent now. A few times i layed on it until 120-130 mph and some passengers were shocked with what it is doing now. That is with slight increase in boost under 3200 RPM and stock boost 3200 RPM to redline. I actually have a great desire to reprogram the transmission now so it is not downshifting all the time. Of course if the RPM are under 2000 there is some lag, and it gets really bad at high elevation.