Since mad jock introduced the physics into this, and to amplify his point about approach speeds:
Height (potential energy) and speed (kinetic energy) are both just energy, and we all know you can convert between the two by pitching up or down, but you don't often see the equivalents calculated.
At the kind of speeds we are talking about 15kts excess speed is equivalent to about 100 ft excess height. With typical L/D ratios that is several hundred feet of runway, and of course ground effect 'improves' the L/D ratio.
Since excess height is a lot easier to spot than excess speed, isn't this the biggest argument for nailing the POH approach speed from the top of final approach?