The rendering time varies both with the settings and with the renderer. With the default renderer it takes between 5 - 10 minutes, but using the optional Simple Photo Renderer, it takes 15 -30 minutes. It might have something to do with the different way the bucket size is handled. The studio has a rendering farm with several Mac Pro 12-core computers connected with fiber-optical cables.
When I use the default renderer, the rendering window is entirely covered by small different colored buckets, but when using the optional renderer, the buckets are a lot bigger and fewer, and works slower. I found this out just by chance, and I have not done any real testing of this. I prefer using the default renderer for interiors, and use the optional renderer for exteriors , since the enhance sky brightness sampling generally gives better results.