I'm a FO on a cj1+ and the commander I fly with (used to fly A320/330) expects me to be at Vref+10 over the numbers (in calm conditions, otherwise the wind corrections as mentioned in some previous posts apply) and to touch down on the runway surface with Vref (never below!). Another commander, however, who has always flown small business jets, applies the power-idle at 50ft AGL technique and then flares the a/c much like a C172, I watched the airspeed sometimes going down to Vmca before the wheels touched the ground. I reckon the former landing technique gives you a greater safety margin.