The issue, previously noted by me, was that the time delay before a long press on the shutter button kicked off the full resolution video capture was just a fraction short, meaning that it got in the way of using the shutter button for, you know, taking photos(!) You set out to take a snap and ended up with a 0.2s video most of the time.
With today's update, this is fixed, the time delay before video capture is now a fraction of a second longer and better tuned to real world use.
In addition, reliability of launching Lumia Camera from the 930's shutter button seems better. Previously, when the device display had been off and in portrait mode, a long press on the shutter button often did nothing - it has worked so far with this version. Comments welcome, in case I'm imagining this part!
Some people are reporting a reduction in lag times when rotating the phone after taking a photo, though do note that there's some heavy duty processing going on for a few seconds after a snap, so I'd expect some issues. Still, hopefully the processor cores are now used better to allow a faster response from the UI.
As ever, if you want a part in all this, check in the Store for updates!