Check out this quick demo of some of the Lumia Camera features with Lumia Camera 5.
A Nokia Lumia 830 on Denim without Lumia Camera 5 starts up about the same speed as a regular 1520 – a bit slow.
Now, you can see that from pressing that camera button to getting the viewfinder is a lot quicker meaning that if something spontaneous happens, you’re more likely to capture it.
There’s been quite a few times that the 1520 has taken too long to start and I’ve missed the picture. (My Note 4 takes just as long if not longer because of the lack of camera button. This surprises me since the camera is nothing special and doesn’t need to do what Lumia Camera is doing).
Processing of a rich capture image took a little bit longer (though you can view the image immediately). I suspect that the more powerful Snapdragon 800 chip will make the 1520 processing much faster.
Whilst they also demo rich capture, you can’t really see much use of it in this scenario.