I think you're talking about my plane... red vertical tail and wing tips w/ stripe and grey nose, and Randy has the diagonal orange wings and does use a flight camera (board cam) and a GoPro recording now with both on a video switch so he can see what the GoPro shot is seeing for better filming ability.
I've used the GoPro as my main flight cam for over a year now on every FPV rig I've run. Compared to other board cams it does generally not do well in low light situations, or in heavy clouds that blow out the contrast against the ground. It's worthless for night flying and you need to be sure to land by the time you're seeing 1 bar left on the battery or you'll be getting a quick countdown and then... bye bye. You can power it from the plane, but I've never done that as in the event of power loss the GoPro will not finish writing the file whereas if it is powered by it's own battery it would not be effected.... but in a hard crash that might not matter.
For many, all that right there is a turn off and why they don't like the GP as a flight cam compared to, strap it in, push record and if the battery dies then it dies and it will stop the recording.
Anyway... for me the HD footage is something I like to edit so I want to see what the GP sees, and in the end the footage looks much better than the transmitted footage does from the live out, so it's always nice to watch over the footage again and you see so much more. Who nows, I might try another cam setup like Randy does with a switch so I have the best of both worlds. After all this time on the GP I'm sure using a nice board cam will be like taking sunglasses off inside.