https://www.youtube.com/watch

Quiet in nominal operation, but can sometimes get silly.

I used to have a CloudKey V3. The installation of UDMP went quite well. I created a backup and then restored it to UDMP. What can be a bit tricky, however, is if the constellation is such that the UDMP then takes the same IP as the active router. I then set the UPC router to bridge mode.
Attention: For the setup, the UDMP wants an internet connection ... Only later can you set up users who can also access it locally without an internet connection.

The noise level is acceptable as long as no hard disk is installed.
However, I clearly advise against this product. I already own the second device and this one also had a hardware defect after a short time. Support directly from Unifi (by phone) is neither in German nor in English.
Many features that are self-evident in my opinion do not work with the device.
In short: Hands off!