[Jimmy C]

It's a pity there doesn't seem to be a translation of DVD 9's booklet. The entry for W.A.S is there.

Originally Posted by arkhangelsk

It doesn't explode. It bobs around at a walking pace,

You might consider that it actually uses more energy to just bob around than to zip through the area like a rocket. It uses X amount of magic per second to operate, regardless of the speed it's moving. As a result, it eats up more energy per meter at a walking pace compared to a flying pace. It's just like how they say your car's fuel efficiency is better at higher speed.

except for the energy used to counter AMF (which can be solved if we figure the AMF is relatively weak and/or the anti-AMF measures are comprehensive)

The AMF may be "relatively" weak to Nanoha as a whole, but it's almost certainly overwhelming to a dinky little sphere of magic. Next, no matter how comprehensive the anti-AMF measures are, they are composed of magic, are worn down by the AMF and must be maintained by a continuous input of magic. Without that input, it's just a matter of time before any anti-AMF measure ceases to exist. It's not like putting up a piece of physical armor against radiation, you know.

If the AMF strength suddenly deviates from prediction (say a single AMF generator was broken on that multi-hundred year old ship) the extra power might become a power surge that would fry every "circuit" on that silly scout round. POP!

The thing is repaired you know, courtesy of its self-repair systems. And once again, you're thinking of an immaterial construct as if it was a physical object. Rather than frying as if you put too much current down a wire, it could absorb the excess by, oh I don't know... expanding perhaps? I'm sure they can tolerate a range of input magic levels. More to the point, even if the AMF generator was down in one section, it'll still be up in others, that'll balance out any surges.