I'm surprised at this - I run four pfSense boxen; my two homebrew ones on repurposed old machines have both died on me at least once, and the two running on purchased pfSense hardware are still up & running. Anecdote != data and all that, but I'd buy their hardware again if I didn't have a large stack of machines I can reuse for "free." (ahem. free does not count my time or that of my students, but sometimes it's fun to admin things a little.)
Do you have any experience with the lower end SG-2220? I'm looking at replacing the Aspire Revo AR1600 I've hacked into a firewall at my aunt's shop running Sophos UTM with something that doesn't require a USB NIC, it looks like a pretty good value at the price.