Hi John,
I appreciate this wasn't done in the past but most of those models of firewall you state have turned up in the ShadowBroker NSA dump. Juniper, asa/pix, also fortinet, Hauwei. To my mind every small extra layer of security we can implement such as OTP on the GUI we should as network security devices are a key target. For someone like myself as an MSSP wanting to recommend pfsense to SMEs and then actively manage them it would be a nice to have. It's becoming standard on a lot of servers, honey platforms etc. Like long unique passphrases, password managers, as well as everything you mentioned in your posts. An attacker could completely pwn the terminal i use to connect and creds by they would need to have access to my iphone as well. every small layer adds another sometimes huge cost to an attacker than can make the difference, deter them and add weeks to their attack. Pfsense is a really solid bit of work these days, stable, small things like better clamav sigs & OTP and maybe a few more really help it compete with the increasingly security conscious.
J