Ok here's mine again...a shameless copy of the original post
The new GI method offers more detail in shadows. Left is "old", right is "new".
Before this new method lighting/shadows on vegetation and shadows of displaced terrains were "missed", just to put it simply.
This new method gives more depth to your lighting and shadows, strongly emphasizing the 3D feel of your image and thus makes things feel less flat.
In this specific sample the effect in displaced surfaces is huge. This is rendered at default settings.
Using this new GI makes you think twice on how much displacement you should apply
So what we see here is that previously, for the left image, I overdid the displacement to get the look I wanted.
The new GI method is more accurate and now shows nicely the flaws in my displacement setup.
Next example, if anyone is interested, will show the difference in vegetation.