You're right - there's a lot to like about the RX10 Mk1, however there are a few things that I'm looking to improve on. The lens, while pretty good optically, has a few features which for me get in the way of usability - it's fully fly by wire and has a ring shared by zoom and focus. When zooming it has a really long endless throw and while recording its zoom is incredibly slow. The servo nature of the zoom means I nearly always over or undershoot and need to narrow down on focal length, all of which takes time and is an irritation (I come from an slr stills background and I guess I'm just used to the direct, precise feel of mechanical lenses!). When in manual focus, the ring becomes focus (and has the same less than precise feel) which means zoom is delegated to the rocker around the shutter release. This has the same focus speed issues as the ring and on my camera, I've had two camera body upper sections replaced under warranty due to this rocker sticking and refusing to stop zooming. Even with careful attention to exposure, low light performance is at best mediocre but is OK up to ISO800 and useable with noise reduction to ISO1600 - I know that the GH4 is not known as a great low light performer but at least there is the option to use fast primes and gain a stop or two. I'd also like to be able to get a slightly more 'cinematic' look to some of my stuff - the lens / sensor combination of the RX10 is limiting in this respect. The GH4 seems to potentially provide much more flexibility in this respect (albeit, at a cost - an endless lens buying fetish!) So, decisions, decisions - the Mk2 RX10 addresses a few of my reservations with the Mk1 but its main selling point seems to be its great high frame rate performance - this isn't a big draw for me and it's expensive. For not an awful lot more than a Mk2 RX10, I could get a GH4 / 12-35 combination, together with it's still excellent performance / codec and flexibility. Thanks again for the input and making me properly think about what I need (and want!). Matt