Dedicated Netgate appliance or Dual NIC PC?
Any difference in stability, particularly with power loss and the unit coming back up by using an appliance based pfsense firewall from netgate vs pfsense installed on an intel PC?
I need a reliable firewall solution for a small business who need VPN etc.
For business purposes I would go with a Netgate appliance.
If you expect regualar power outages go for a small UPS in either case, the filesystem is not designed for constant hard shutdowns.
Any reason why an appliance?
You get the Software and Hardware from the same provider, they work 100% together and you have good support.
If you get an appliance from us you know it will have been tested for any new release, there's far far lower chance if hitting some obscure hardware issue. Also you will be helping to fund further development.
If you can't guaranty the power supply, even with a UPS, then you should enable RAM disks to reduce the chances of causing filesystem damage in the event of a power loss. You might also consider installing using ZFS which is generally more resilient.
Fully agree on this.
It's worth spending some extra money to avoid playing the "it's not our fault" (TM) roulette with your vendors