Hi Ian,
I did these in Sketchup, although I started the process with Maya. I found Sketchup is better than Maya for architectural models, but I would still do organic objects in Maya.
The biggest challenge was making sure the objects were manifold. Sketchup (free version) has no way of repairing holes in geometry, and will only identify flipped normals. I tried cleaning them up in Maya, but I still had issues.
NetFabb seems to have solved this issue for now, but I don't want to rely on software to clean the models. To that end, I've had to change my approach to modeling, since Maya is very forgiving of non-manifold objects. :???:
If you have any resources you can point me to, that would be greatly appreciated. I'm also open to learning new software.
Thanks,
Mark