The FWG provides most of what I had in OPNSense without the hassle so it is just much easier to set it and forget it.and not worry that something needs updating or is broken.If the top result for 'Mikrotik configuration' is accurate: Overall, I didn't mind working through the weird stuff when I ran it, but forget asking other family members to troubleshoot it if you are away. There were some other things I am probably forgetting as it has been a while since I turned that machine on. That may have been better with the faster machine though. I have a 1/1Gbps line and performance went from line speed to ~600Mbps with full CPU in the VM with Sensei. Hardware acceleration had to be turned off (per OPNSense documentation for VM setups) which really hurt performance if you wanted to run their Sensei package. There was an issue with the VNET drivers during one of the OPNSense upgrades that did not get fixed for a couple versions (chatted with their support). Plex did not always play nice as the passthrough video card support in LXC would sometimes lock the box up (not common but it happens).

Proxmox needs updates, when it updates (some updates) you have to restart everything. Here are some of the things I encountered: I ran the above setup for a little over a year with not too many issues, however, that setup required a lot of maintenance to keep things running.

I did not run wifi on it as it was connected to better APs on the network (and that machine lived in a metal SMC). I ran OPNSense in a VM with Plex and a couple other things in LXC.

I actually did what you are talking about but using the i3 Protectli (FW6B) and Proxmox (paid subscription).

Protectli fw6e