Until my DVR arrives I have no recorded fpv video, only a quick shot about the M150 prototype v2 maiden:
Until now I never needed any DVR as my 300-sized quads all use the Mobius cam either for fpv view or for HD recording.
And to get back to the main idea, I forgot to mention some other aspects.
Beside the portability also the mobility and legitimacy was important, when planning the build.
With the 50mW 2.4G TX and 50mW 1.3G vTX the usage of these frequencies
with the radiated power is nearly lawful, at least here, in Hungary, Europe.
I say nearly because transmitting on 1.3G is illegal, even at this low power,
and also having a camera on the quad is illegal as well,
not speaking about the other permissions, from air traffic control and land owners.
So, if the quad can not fly, keeping the law, then let the whole solution be mobile at least,
to allow fast packing and disappearing.
Also, the size of the quad is quite small to avoid discovery from a longer distance.
I am also thinking of getting the quad a bit stealth, by using special propellers and camo painting.
Regarding the props, I would need help as I am not a physicist, but the camo is doable, I think.