I use it for my mailserver (thank you openbsd.amsterdam), for the gateway in my homelab, a dedicated OpenBSD VMD machine in my homelab, and on personal machines (Macbook Air M2, a Thinkpad X220 and on a T480 that dualboots OpenBSD/FreeBSD).

For mailserver I think it is the best option. And for Gateway, PF is just wonderful.

But even on my laptops I enjoy it. It is rock solid, and I have pretty much no complaints.