I almost went with the opnsense route as well, the versatility of this device and the fact it can run on lots of hardware configs makes it hard to find a hw/feature combination that will serve my needs with low power usage and no fan. Also I hope that mikrotiks fw updates have a lower chance of breaking my setup as I’ve read some bad experiences with pfsense/opnsense updates in the past.
None the less I do like the opnsense setup and might add an additional opnsense vm in the future to play around with!
Thanks, that makes a lot of sense! Will certainly look into getting a NVR in the same vnet as the cams if I ever get them. I was planning to have devices exposed to multiple vlans (e.g. home Assistant). However I wasn’t sure if that is good or bad practice (since it opens an attack vector to jump across vlans). I could always opt for a L3 switch if need be.