I've tried the Carrara demo and i'm sorry to say that i'm just not comfortable with it.  For me it's no replacement for Bryce.  What should be done is for advanced Carrara features to be implemented into Bryce, although any advanced models can always be made in some other 3D app and imported.   For overall scene manipulation and final rendering, Bryce excells.  Actually, if I could just get ambient occlusion for that realistic shadowy effect I could stick with Bryce forever and ever. 

By the way, I haven't posted anything for months because of endless delays in getting my new workstation up and running, but i'll be back as soon as I can.

"An Example is worth Ten Thousand Words"