Uploading to the GearVR takes longer since there is more optimization required. If you only need to publish to Desktop VR (Oculus Rift and HTC Vive), you can get a much faster build by selecting "Desktop VR Only".
This option determines if you model will be processed with it's original textures or if it will be shown as a white sketch model with all textures stripped out. Sketch mode is a great way to draw focus to the space rather than the materials and colors.
Basic lighting will speed up the processing speed significantly, but it will not show sun shadows or ambient occlusion (dark corners). This is ideal if you require fast iterative model processing. The Detailed Lighting option will take longer, but will show solar shadows and ambient occlusion.