We used Darktree to create some of the more complicated textures used for the movie Red Planet. For example, we used Darktree to create the rear blue solar panels of the Mars-1 as well as the pod foil, the clouds for the Earth shots, etc. Your program rocks. What is amazing is that you cannot tell the difference between the practical model used in the movie (only 5 or so shots) and the digital model we created (over 30 shots).
Darktree gave us great command of the procedural shaders. There are things that we can accomplish easily with Darktree that would otherwise be impossible to get in other shader programs or plug-ins that we have tried.