This is my first space landscape created using the Blender & GIMP combo. Overall all went well. The only thing that bothered me a bit was that in Blender (v2.69) I was unable to adjust the amount of horizon and zenith colors visible in the image in relation to each other. There is either no way to adjust this or I couldn't find where to do it. I have fixed the colors in GIMP, but things like that should be doable in Blender. Rendering time at 5760 x 3240 on a dual core 3GHz Intel E6850 CPU, 4min 3 seconds.

As for GIMP, I'm impressed how much faster it got. In the past, my main objection against using it has been that working with high resolution images is too slow. This is no longer the case. So far it seems as fast as Photoshop. I wonder if GIMP works faster under Linux?