Fran, I guess one day I also will be able to talk in abreviations,no your not missing out on a hidden feature in Bryce. Istant Back Lighting was just a stab in the dark as to what IBL is!!
"Newbie Ahoy"
The RR (Random Replicate) you mention could that be used in a terrain situation to create city blocks of various heights, a city scape if you like?
As I have this urge to create a city then make the camera fly through the streets between the blocks.
Is this possible in Bryce ?
I had a try at animation without reading up on it .Imported the Blender monkey,opened the animation tools. Created Sky. Sea, with great sunset relections ,topped it off with Gold Blender Monkey. Moving to the timeline I moved  Monkey around etc etc.
I in all done 37 frames. A tad over one second.
One hour and fifteen minutes later the render completed!!!!!
I must have been doing too much at once.???
Many thanks for all your freebies out there Fran.