Solid Signal has Xtreme Signal antennas HDB91x and HDB8x that look like they heavily rip off the Antennas Direct 91XG and DB8e. I was looking at the specifications for them, and I saw a graph twice. The manufacturers provided antenna gain for the HDB91x and HDB8x are identical:
http://manuals.solidsignal.com/hdb8x-gainchart.pdf
http://manuals.solidsignal.com/hdb91x-gainchart.pdf
Even if the gain curve for either antenna is right, the bulk of the gain is above the currently used TV spectrum, around channel 64. Also, why show gain for 800 to 900 MHz? 70 to 83 have not been TV channels for a long time.
So, I would avoid has Xtreme Signal antennas.