I've built my new pFsense box, using the Jetway JBC200F9N-E4IN-B (5 port Intel). It was an easy build, as you only had to install RAM and hard drive/SSD.
I'm not sure how to run network tests, but for my 300/20 connection, it is fine without any problems.
https://forum.pfsense.org/index.php?topic=97384.0