It depends. The best thing you can do is get measured for your power output. Folks with a lot of power (like Jan Ullrich) in their pedal stroke will tend to push bigger gears and go faster with lower cadence. Then you have the spinners who rely on the faster speed to propel them at a faster speed, and it works for them.
If you have a lower power output, it may not make sense to do much of this type of training.
Koffee