just wondering since both are unbiased, how did you manage to cut down the rendering timeto 20 min and increase the resolution compare to your first render? to my experience, the higher resolution you set the longer the render time it will take, but in your test, it's the opposite.
Jon and the Thea team can answer this better than I, however it has been my experience that close up/detail renders almost always take longer, which explains why Jon's first render took so much longer at a lower res than the full shot.
I was doing several shots yesterday (in Vray) on a project and every close up took about 2-3 times longer than the "full view" shots did. It seems this is always the case at least with my projects.
I'm assuming that this is becuase of the amount of detail and higher quality (of light, shadows, textures, etc.) needed for the program to reslove these details for the close up's.
Maybe someone can explain better than I why this occurs, I only know that this is normal.