Oops, sorry I didn't do a search first, but thank you Matt for the link to the other post. And sorry Andrew if I have derailed the RX10, I thought here might be an appropriate place simply because of your points about the RX10 AVCHD and poor video in motion shots. Your comments about the d5200 seemed relevant to your criticisms about the RX10, but I'll work harder to keep my questions aligned to the camera posts themselves, rather than the nature of video.
Cheers to you!