ND, or not too ND?

Let's see how extreme ND (neutral density) filters compare with stacking using milder or no ND filter. Extreme ND filters cut light enough to allow long, motion-blurring, exposures even in bright daylight, but there is another way: image stacking of shorter exposures. Instead of one 16s exposure, you could stack (average) a rapid sequence of 16 1s exposures using a much lighter ND filter or none at all. Stacking should give higher IQ (e.g., lower noise) without needing the expensive filter. This challenge is to determine if it does... and you should label each submission with number-of-shots@ND-stops, e.g., 2@ND10 would mean two shots with a 10-stop ND filter.