Earlier quoted context omitted.
I also use a MiniPC running pfSense and couldn't be happier. I made the switch 3 years ago, after running a Linksys WRT54G-TM on OpenWRT for 5+ years. pfSense is simple to get started with, powerful enough for small to medium businesses and "just works." The initial setup might be a bit more $$$ ($150 for hardware), but it will last you a long time.
Which MiniPC did you use? I'm considering a similar setup, so options to consider would be welcome.
I added a 32gb ssd drive and a USB Ethernet dongle as well (for 2nd interface).
The box has wifi, but no driver support from FreeBSD. My WIFI is supplied via a UniFI AC LITE.
1. http://www.newegg.com/Product/Product.aspx?Item=N82E16856164...