But for me, as a consumer, I have to take the vendor at their word. The drop in penetrating power of the battery powered unit was noticeable and the vendor was adamant that no unit should be powered via an adapter.
So my choice was to look elsewhere and another vendor who was willing to provide an almost cost free 3 month trial sold a more powerful/sustainable unit with an adapter.
I am sure if I wanted to I could start doing research and educating myself on how to build adapters and zapper and whatever. But in short I really don't want to, this leaves me with what may be exaggerations by a vendor. But as long as the thing works and works more consistently then the other I don't really care.
If there is a better zapper out there then please let us know (I still have 9 weeks left in my trial), but don't expect me to go and buy a soldering iron :)