Thanks for sharing your progress and experiences, with some nice pics as usual
I think they can be better particularly for moving platforms. I remember a great video which I just posted which explains why circular polarization has its advantages!
Otherwise your mount looks great, did you manage to have a flight with it yet? In my opinion I prefer to have the FPV camera not to be stabilized so I get a better feel for what the aircraft is doing, but I guess if you are recording the video feed from your quadcopter having some stabilization makes things much nicer to watch!