I think the point Smolck is trying to make is that the M-cars have gears that are spaced just as far. In fact, the Z4M gearbox is the same as the 330 6MT box (though the input spline itself may be different). And the combination of the higher redline and shorter diff makes it so that the M3 and Z4M reach their redlines at the same respective road speeds.
Now the reason it isn't much of an issue on the S54 equipped cars is that we have really flat torque bands. While our peak torque is at 5k, the torque at 2k is damn close. So pretty much no matter where or revs fall, our engines are ready to respond.