My saddle is lower that what a normal bike recommendation would be. It works for me and makes sense. The higher the saddle is in relation to the pedals the more leverage you have but a slower cadence can be maintained easily. A high cadence on a bike my be 90 rpm but a normal cadence on a uni may be closer to 120 rpm. The higher the saddle is in relation to the pedals the more the knees have to flex and that restricts higher speeds.