Question about dual linear polarisation on panel antennas

Builds Antennas
1

So I was looking at these two panels of which the datasheets are attached, note how one has dual linear polarization, vertical and linear, each coming out on a separate connector, while the other only has vertical linear polarization. How useful would this feature be for an OpenHD build to have both vertical/horizontal polarization? Does it help with reflected signals or such? Edge cases where a packet might otherwise be lost?

Both are on sale locally for $35USD on clearance. panel antennas.zip (803.5 KB)

Screenshot of the smaller one which is a ARC-PA5820B01:

ARC-PA5820B01
ARC-PA5820B011015×599 29.6 KB

And the larger one of the two which is a ARC-PD5823B88:

ARC-PD5823B88
ARC-PD5823B881016×636 33.1 KB

A major difference between these two panels is their size and weight. For an extra 3 or 4dB it’s 1.86kg vs 0.59kg which is considerable, not to mention overall size. I’m strongly leaning towards the smaller one just because of the weight and bulk, besides, 20dB should be plenty.

2

Asking on telegram the answer I got to does it help was:

in most use cases - no
reflected vertical won’t become horizontal, problem is that it is coming different way compared to main signal and if they come at different phases with main signal - it may kill main signal due to interference. Cross-polarisation won’t save from this in any way.