Low+ will give long render times because of the fuzzy tracing on the specular sampling (colors from adjacent materials reflecting sofly in adjacent materials)
If you are using Light Emitting surfaces, this is what is causing long render times...
Low will not look good with soft shadows. So using the alternative AA methods I mentioned early is the best alternative. Or set sun to not have soft shadows.
If I were in a big hurry I would reset all materials in the scene, make sure I set all mesh emitters (light emitting surfaces/faces) to "fake" and put a spot light below the mesh emitter... set spot to be power of 5, hotspot 90 falloff 170, radius .1
Tracing soft shadows on all the lights, tracing fuzzy reflections in every surface with specular, tracing specular reflections on all those surfaces for all those lights, etc, just plain means long render times.
Set all surfaces to be Generic:Reset
Then only for the floor and any KEY surfaces, set it to have some reflection in it like a Plastic:Satin with some bump. It is the specular on so many surfaces, not the bump alone, that is adding to render times.
Fastest rendering light = spot
Point lights = approx. 2x as long as spots
IES lights take more than 2x longer to render than a normal spot.
Light Emitting Square = min. 3x longer than a spot or more.
This would be a challenging scene to light 'quickly'... it would actually take a lot of work to get this scene to look realistic, yet render quite quickly. Either I would just light is as you did before and do all materials as the 'should be' and render with progressive render, or I would use some creative lighting techniques to make it look 'close enough'... but you will need to get rid of all the specular reflections on so many surfaces. Possibly turn of soft shadows for all your lights... that would render much faster.
You could in future learn to net render Easy 09 using Kerkythea on 5 machines at once.
