I just built a pFsense firewall with one of these:
...iperf is coming out with ~420Mbits per second through it, from one inside interface to the other. That's plenty of speed for my 130Mbit Charter connection. I've also ran Sophos on it with the same performance, but the Sophos home license limits you to 50 active IP addresses at a time, and I was always going over that limit.