To dither or not to dither?

I have two similar sessions on the galaxy NGC3628, the ‘dimmer’ member of the Leo Triplet. One session was done without dithering, the second session with dithering. So maybe it’s educational to really compare the two results and verify what the effect is of dithering?

NGC3628 36x300S 800ISO Nikon D750 Esprit 120mm F7 NON DITHERED
NGC3628 54x300S 800ISO Nikon D750 Esprit 120mm F7 Dithered

The difference in background noise should be clear.

To be complete: the dithered image was 54x300s or 4hrs 30m exposure, while the non-dithered image was only 36x300s or 3 hours of exposure. Both nights were equal in quality.