Just stumbled across this forum - excellent stuff, I feel very out of touch.
Purely from a professional view the aeroplanes performance is based upon crossing the threshold at 50' and landing ON the numbers at the calculated landind speed - depending on the manufacturer (how is this word spelt ??) that could be Vref, Vls, Vref-7 etc etc so for you guys planning to take the pro's line then very definately aim for touching down on the numbers.
Anything past the numbers is IMHO very gash, whatever type and size of aircraft you fly.
That said - safe flying guys and gals