"...but I doubt that the other Zapper is far superior technically. I mean, it depends who is measuring it."
No, it doesn't.
When the preferred characteristics of an energy source are clearly defined, or even not-so-clearly as is the case with zappers, then technical superiority is not subjective. Between Clark's "research" and the concensus opinions and experiences of the zapper community, a set of minimum desireable characteristics for a zapper design is pretty well defined. Amplitude, harmonic content, waveform distortion under load, etc. vary from one design to another, and the differences are clearly observable. Persons other than me have assigned value to these, such as a rich or strong harmonic field (one with many harmonic frequencies or higher amplitudes) being "better" than a thin or weak field (one with fewer frequencies or lower amplitudes). Once the value has been established, measuring and evaluating different designs is straightforward. True, anyone can cook their data, take scope images under different conditions to exaggerate performance, or make unsubstantiated claims. But absent such intentional biases, *technical* superiority is independent of "who".
As much as it pains me, I agree with PZ about zappers based on gate oscillators, such as the original $10 zapper using a 4069 hex inverter chip. The output stages of these devices (early generation CMOS gates) do not have the output current capacity or a low enough output impedance for this application. This is clear when observing the output waveform distortion under load. Particularly, the rounding of the square wave leading corners means the amplitudes of the higher harmonic frequencies are decreased relative to those produced by a circuit which remains "square-er" under load.
"I would like to know what "Dr. Clark's latest specifications" are and where they are coming from..."
They come from one of her later books. She added one resistor to the original zapper design (causing an offset of about +1/4 volt at the output), to "guarantee" that the all-positive output was in fact all-positive. I think this was totally unnecessary, and in fact detrimental to the circuit's overall performance.
1. The chip used in the first design has no negative power supply input, and no internal mechanism to generate a negative output voltage. In fact, the output already is offset about 0.05V to 0.1V above ground under load. Some scope shots show a small undershoot on the trailing edge, extending *slightly* below ground. IMHO, these are classic examples of bad scope grounding technique, not evidence of any kind of "negative" output.
2. The offset resistor increased the low output voltage by about 1/4 volt, but increased the high output voltage by *less* than that. This means that the overall amplitude of the output waveform was in fact *decreased*.
3. While the composit output waveform appears to be comfortably above ground, the negative half-cycles of the first (and third?) harmonic sine waves still extend below ground.