A side by side for quick reference. The top is the old and the bottom is the new.
In the new version all haze was disabled, the white sunlight was replaced with a reddish tinted sun, the white secondaries were changed to a bluish color, and many materials were updated. The sky was also updated.
It really makes a huge difference when the sunlight has a tint and is not pure white. While on the subject of sunlight the default sun is already dim at full white it gets very dark when you add color to it. This is another reason why replacihng the bryce sun with a radial light that you can control yourself gives much better results. Both versions are lit with radial sunlights, although the top has soft shadows a step I did not take in the new version. The "heat" radiating out of the scene would not be possible with the bryce sun.