My parent's house has a similar report (
here), so I'm familiar with rotten conditions. As @GUM says, the HDStacker's vendor does not publish performance data similar to other vendors, so it's hard to do direct comparisons. I've not seen one in the wild, but I have concerns about the connection between the top and bottom arrays nevertheless.
The recommendations here come from practical experience and understanding of the physics involved. Without casting aspersions in any particular direction, there will always be vendors that claim fantastic results that don't hold up under closer inspection. We try to be careful to recommend equipment that has been proven to work under the circumstances described. That does not mean there isn't something innovative out there (see the latest VHF antenna from AntennasDirect for example.)
There are a couple of places that give recommendations for deepest fringe reception. The OTA forum at digitalhome.ca is one of them.