Very good
Possibility of connecting 4 4K 21/9 screens to a Windows server which has a simple VGA output.
Small inconvenience when starting the server: the video signal is not displayed on the screens, the VGA output of the server must be used as a relay.
No problem if the dock is used from a laptop.
Also, I sometimes notice a flickering on the screens.
Finally, it doesn't work well on Linux (Ubuntu 20.04), only 2 and a half screens are displayed, maybe there are drivers to install.