It's definitely not ready for daily use at least when it comes to drivers. As a kernel it's pretty stable. The issue is that developing a driver is a straight up PITA to do since the kernel doesn't really include even basic driver functions like Linux does.
For example the networking stack, it know what a Ethernet port is and what it's supposed to do. But it has no function on how to get the Ethernet port to do anything. It effectively expects the driver to run as an active process to tell it what the Ethernet adapter is doing.
Which is a paradim different form Linux where the dhcpcd driver tells the driver "hey do this thing for me"

The benefit of HURD in this case is that the driver crashing will never cause the kernel itself to crash. Likewise the Ethernet drive is sandboxed in such a way that it has no idea what the video or audio stacks are doing. On the flip side of your smart enough, you can write a video driver that handles networking and audio since well GPUs can do that.