Pre-rinse, here. I have read the items that says it uses more "energy" for the hot water pre-rinse, but we two are
really pretty low impact, energy consumption-wise, so I am not hand wringing that crap.
It seems to get the major junk off, to allow the DW to clean better, and our dishwasher(s) are not top of any line, both on the Mtn and in FL.

I have read several snippets that suggest "some" food/gunk on the dishes/silverware is rec'd as the DW soap supposedly works better when it has some gunk to attack and "eat", fwiw.

I don't obsess over DW performance, brands, ratings, etc...they all work ok, and for me there are other things to sweat.
GL,mD