This summer I had a router running OpenBSD on the older apu1d and was seeing nearly 700mbps on iperf with a basic rule set. But I don't know how iperf relates to real world performance.
iperf has been, at least for me, a good benchmark for how fast file transfer might be, if everything goes well. Usually they are a bit [say, NFS] (or much [say, NFS on Windows]) slower.