A bit of thread creep here, but:
Additives are half steady headwind component plus all of gust factor. Minimum Vref additive is +5, maximum +20.
With autothrottles on to touchdown (autoland) its simply +5 (due to TMC protection).
Spin it ever how you want. I very seldom hear anybody from AA, UAL, NWA, or CAL. Anybody else who flies a 757/767 never has to ask for a windcheck. Is there that much difference between different companies trying to fly the same airplane. Delta seems to be the only one who does this. I don't have a dog in this fight but you guys are the laughing stock when it comes to asking for a windcheck.
The wind is whatever it takes to put the airplane safely on the ground.