Some observations
(a)
The 727 didn't like Vref+5 always felt better +10
If my recollection is correct, the -100 was certificated on the basis of stall speed, while the -200 used minimum steady flight speed, leading to the common practice of carrying a bit extra on the later aircraft. I suspect that most (many ?) of us preferred the -100 for landing ease.
(b) the steady wind/gust (Boeing) rules of thumb reflect the reasonably predictable nature of a steady wind (intentional speed bleed into the flare) and the randomness of gusts (maintain the gust additive). This was discussed at length in an
old thread. The slightly different tack adopted by Airbus indicates that the subject is a bit rubbery and that the goal can be achieved by multiple, similar techniques.
(c) the certification landing animal is a flight test black art resulting in a substantial operational fudge factor (100/60 or 1.67) for the final AFM data. Those who have been involved with performance takeoff and landing trials will understand what I mean. Rather than agonise over whether a particular aircraft was certificated to this or that, on the line I prefer to consider the underlying intent of the exercise - which is to stop comfortably on the runway .. and I hold that the AFM is the pilot's friend ..
(i) follow the AFM guidance, fly a stable approach, and you are half way to the hotel
(ii) beware of slow speed approaches unless you have lots of instantaneous thrust to counteract gust problems
(iii) beware of low approach path landings lest the undershoot area beckon you
(iii) beware of high speed or high approach path landings lest the overrun area beckon you
(iii) if the aircraft is somewhere near (say,
± 10 kt) the AFM recommendation at screen/touchdown, and touchdown is in the nominal touchdown region (typically around 1500 - 2000 ft into the runway) then there is a high probability of a successful outcome. Conversely, if not, then perhaps one ought already to be on the missed approach or doing something else appropriate and urgent to address the matter.