Before I start, let me say I am a complete Tech Dinosaur. However, the only video footage we personally have of our many rides with family and friends is footage on an iPhone. Apart from Mrs pillion using the iPhone vertical instead of horizontal, it is as good a footage of anything I've seen posted here. The quality is second to none apart from it not being as stable because it being hand held and not mounted, but the picture quality is fantastic.
Just my 2 bobs worth on the iPhone thingy's. Not that I care less. Just my experience.
However, I'm still trying to 'score' a bike mounted camera of some description because my pillion doesn't participate near enough. Don't tell her I said so.
Cheers.
Skip.