The aspect that I prefer about the wing down technique is that, once you have it stabilised, (well before the threshold), there is not much else to do other than make a normal landing. Naturally, it can get tricky at night when the w/v has a habit of changing rapidly during the last 150ft but you get the same problems crabbing it in as well.
One thing is for sure though - for these reasons a x/wind landing is far more difficult at night than during daylight (unless you are near the tropics but let's not go into that).
My understanding (just a pilot's working knowledge) of the Boeing autoland in x/winds is that it ignores up to 5deg of crab and then uses forward slip (i.e. wing down) to deal with the rest; but only up to 2 deg of slip max. Up to the 25kt x/wind maximum therefore there cannot be a risk of scraping.
The only problem with wing down is that you can apply more forward slip than necessary and not know it - which is where many pilots go wrong - arriving at the runway with too much wing down. You should never require more than 3 or 4 deg of slip (bank) even for max x/winds.
I would add though, that I have never flown 747's so what would I know about it? Bad luck to the crew involved though - could happen to any of us.
Cheers
BS