Question about Nuki Smart Lock PRO (5th Gen) CH cylinder

I used to have an older version (2 or 3). It was definitely too loud for me. I only had it for a few weeks at the time. I've had the Pro version 5th Gen. for about a month now. I am very satisfied. It is much more reliable.

There are three speed settings. Faster = louder. I work with the middle one during the day. Overnight, I set it so that the slowest level is active. It is then a little quieter, but works for longer...

I don't have any measurements or exact figures. But it feels quieter. It's also more reliable, nicer and faster.