Bryce Lightning is an added application that allows Bryce5 to use other computers on a network to speed up render time. You only need Bryce5 to be installed on one computer and Bryce Lightning on the rest and you have your own render farm. It divides up each frame into quadrants and assigns a quadrant to each machine on the network. When they are done rendering Bryce5 assembles them into one frame. It's very helpfull and time saving when using Bryce5 for animation. I guess the update fixes some bugs or issues with it.