Quote - Unchecking it will tell Vue to re-calculate the scenes lighting for rendering.  If left checked, just render the scene once and note the time taken.

Doesn't really matter since only one render for a scene is needed anyway for benchmarking.

That is generally true, but not in this specific case. The scene (Radiosity Room from my Vue 9 Infinite) seems to be saved with the indirect lighting map. If you leave it checked, it will NOT perform the prepass and directly go to rendering. Even if you have not rendered it before. Hence the total render time will be faster.

Ciao
TD

Edit to add: This is actually a very useful feature. If you render an image with GR/GI and then save the scene (with reuse indirect lighting checked) the indirect lighting map will be saved, too. When you load the scene in  again you can continue where you left off without having to recalculate the IDL. I use that quite often to speed things up when wrking on complex scenes.