18 Wheeler
I dont mean to be nitpicking, but why would you apply citation theories to flying a 747. I'm fairly sure Boeing do a fair bit of their own research before they advise you that high speed climbs are more fuel efficient in big jets. I could well be wrong, but i am fairly sure that this point is beyond argument.
It is not just a matter of altitude, it is the combination of altitude and distance. i.e Normal (high speed) climbs are a compromise between altitude gain and distance covered, therefore reducing cruise distance as well. It may well be possible to use less fuel to TOC using a different profile than high speed, but what really matters is how much fuel you have at destination, not TOC. Although you may initially gain altitude quicker at 250kts, you eventually have to accelerate sometime, and this is done more efficiently at lower levels where more excess thrust is available.
Bird strikes are a different consideration, as 411a pointed out.