With the extra processing power available, the idea of always on rich capture and always on living images (if turned on in Settings) is a little alarming in terms of storage space, but hey, these babies have microSD support, so just use a nice large card. You'll need it for the 4K video anyway!
Not everything is clear in the explanation, mind you. David mispeaks the aperture for these cameras, plus there's still a Rich Capture on/off toggle in the top toolbar, so we'll have to try this for real to establish the parameters of how it all works.
The phase detection a-f and the larger f/1.9 aperture, allied to the speed of the Snapdragon 808/810 chipsets, should mean very fast focussing and shooting, very competitive with everything else out there in smartphone-land, as of the end of 2015.
Anyway, enjoy: