Not figuring gusts into the equation, on the MD11 we fly Vref+5 which is normal Vapp, until the beginning of the flare when the t/l are reduced to idle, beginning at 50ft or so. At touch down the speed could be anywhere from Vref to Vref less 10. The critical factor would be deck angle upon touchdown, regardless of ones speed, on any particular aircraft if a certain deck angle is exceeded on touchdown there is, as was mentioned in an above post, the threat of tailstrike. Folks flying heavies dont tend to hold it off indefinitely to obtain the greaser, at some point the nose is even lowered so as not to encroach on the tail strike deck angle.