I think Bryce skies are still better than Carrara. However, if you get the DCG plug-ins (and whoever sells Veloute now), you can model and shade terrains better than bryce, from my experience.

I switched from Bryce to Carrara about 18 months ago. I used to use Bryce for occasional terrains and skies. Now it is just for the occasional sky.

Also, Carrara seems to be evolving much more quickly than Bryce which hasn't moved much in the last few years.

Just a few thoughts...

Marc