I use C5 to render full scenes that choke Poser and D|S - I don't like C5's material management system so I do all my texture editing etc in Poser and soft shadows murder render-time. Transposer works briliantly - I haven't had any issues so far with it. The terrain creation seems okay but nothing of the wow-factor of Vue's ecosystems or that cool 3D terrain morphing tool. But C5 has been a great expansion to my Poser toolset unlike Bryce which is too confusing even after repeated use (I can never remember where anything is - even within single long work-sessions - I only know where to vaguely wave the pointer to see what text boxes pop up)

Vue has the superior terrain creation tools - but VI5 was too pricey to get at the ecosystems. If Vue D-esprit 6 has eco's then I'd say hang off buying C5 til you're played with the demo - C5 of course you can buy, try and refund if you don't like it before 30days have expired.

Then again Bryce 6 is due out soon also...they may have solved a lot of it's problems.

Cheers