Oh, I totally get the argument to keep it full. Both the colder thermal mass and less cold air to escape make it considerably more efficient. I just doubt that the thermal transfer from the mass to the newer items is as significant as the compressor kicking in. After all, the compressor is going to flood the internal radiator with liquid far below the ambient temperature of the freezer.

> My LG fridge manual actually says not to put warm meat in my freezer, unless the thing has loads of frozen stuff in it.

That sounds silly to me. In my experience ice cubes freeze within an hour and meat within a couple hours.