Carrara comes from the background of a general-purpose 3d modeling and rendering application, so it's not a great surprise that it deals well with rendering objects, including plants. I've been much less impressed with its terrain and, as you said, atmosphere model (particularly the clouds). Good object rendering is actually quite commonplace - Max, Maya, Softimage (all with Mentalray, or even their built-in scanline renderers), even the lower-end Truespace and similar products, all handle objects well. That's what they've always focused on though. It's a point of debate whether coming from the landscape side without objects (as we are doing) can ultimately yield better results than coming the other direction, but despite the difficulties with objects in TG2 I'd say so far our approach is competing well. We have some work to do to bring object handling up to where it should be, but I think that is comparatively less work than Carrara and the rest will have to do to implement an atmosphere and volumetrics model anywhere near what TG2 offers, not to mention the power of procedurally displaced terrain.
- Oshyan