Thanks, rogueqd, that was the most incredibly useful reply. Really, it's the sort of thing that makes this forum so great.
Hopefully I can respond in kind with some useful advice for people who want to modify their original FatSharks base models to give a better image, especially for people like me who wear glasses (and have bad astigmatism in one eye).
On topic. I have my AXN all set to go for FPV tomorrow, though without the circular polarised antennas unfortunately, as I was sent the wrong polarity sma connectors. Meh, I'll just have to fly close for now.
I have a pan/tilt camera set-up (mounted on foam in place of the canopy) and I have to say that three things struck me straight away.
Firstly, the picture is a damn sight better when both Tx and Rx are tuned to the same channel (duh!!!).
Secondly, operating the pan/tilt head via the pots on the Turnigy 9x is beyond spooky. Watching it work with goggles off was hilarious, and made the AXN look all robot-like...kinda unsettling.
Thirdly, looking at yourself through the goggles is weird too, plus, checking it out through its full range of angles made me get a bit air-sick.... and I was still on the ground!