[seco7]

SL is very useful when rendering animations, though I know not many people are doing that.

I render out a frame from the sequence I feel will be the slowest to clear up, stopping it *just* as it becomes acceptable. Let's say that was SL 14. Now I know I can set all my frames to render to SL 14 and I'll have a good time-vs-quality balance.

I'm not sure this is true. At least not in my experience. I have had several product viz projects with multiple camera angles of the same objects/lighting etc. Although they are all rendered to the same SL, they all (or at least some) show differently depending on what elements are in the camera field of view (assumption about the FOV part). This leads to a lot of post work to balance each shot in a colloge setting.