Vue's trees are more like image maps with a detail mesh where needed. Not really sure how they "Work" but they are a little less system intensive. Bryce 5 trees are nice in that they include roots, there options as far as tweaking the trees are about the same as Carrara 3. The nice thing about Bryce and Carrara's trees when compared to Vues is that you can actually edit them easier then Vues. That my two cents. Brian