Your input is greatly appreciated.
The "shorteners" are no doubt loading coils so each half of the antenna is like a center-loaded 160m vertical that is 35 ft long. Such a loading coil would have an inductance around 120 uH to make the dipole resonant on 160m. If that coil is made to be high-Q, it would be gigantic. It doesn't look gigantic in the picture so it is probably low-Q with lots of self capacitance and that means a low self-resonant frequency. For efficiency reasons, loading coils should never be operated above their self-resonant frequency. In fact, between its 1/4WL parallel self-resonant frequency and its 1/2WL series self-resonant frequency, the coil has negative inductance.
As an example, my large 80m Texas Bugcatcher loading coil (75 uH) has a self-resonant frequency of around 8 MHz. That lower-Q 120 uH loading coil would probably have a much lower self-resonant frequency, probably far below 7 MHz.
Performance is considerably compromised on 160m because the dipole is so short. Performance is considerably compromised on the HF bands because of self-resonance effects in the loading coils. Personally, if they sent me a free antenna, I would use it for a dummy load.
Did anyone notice that they don't publish any gain figures?
One of the reviews, using 160m, said that antenna was S5 on receive compared to an OCF which was S9+10 on receive. Assuming one S-unit is 6dB, that's 34dB difference i.e. compared to the OCF, the AS-2 was 0.04% efficient.