BSD is well designed and cohesive but has many more missing bits and contraints than Linux. So, if you are in its sweet spot, it is awesome and maybe better than Linux. However, outside that it can be totally unusable.
For me, the biggest issue is the lack of software. There is both a mountain of it as it is of course an POSIX compatible OS and at the same time it is trivial to need important software that is missing.
As a desktop, it therefore feels very nice and also very limiting.
I love that it is actually real UNIX with an unbroken history back to the beginning. I find that really compelling. At the same time, I always get “bored” using it because it inevitably does not support what I want to do.
I am still hoping Chimera Linux finds a sweet spot that melds the two worlds in a nice way.
You may already know this but you can run OPNsense on top of Proxmox. That may mitigate the driver issues you are having.