since you can adjust setback (seat post) and reach (stem) on any frame, the frame really determines the weight balance. Time triallists and track riders tend to have more forward positions. Thus you would want a steeper seat tube angle. 20mm difference in top tube is certainly significant. If you get a shorter stem, you're moving your weight back and changing the way the steering feels.

Knee over pedal (KOP) is somewhat discredited. I don't know where my knee falls relative to my pedal