I did not see a difference in mine photos. I do not have a roof on my building yet due to work in progress. I did however see a difference when I turned my regular lamp on. The problem with not having the regular sun lamp is that I am not getting the shadows I want from the portal. This may be due to not have a roof.
One more note… I have corrected myself. It made no difference on my computer screen in Blender. However, It looks like a big difference when posted.