I am currently testing the Asus NUC 13 rugged x7425E with 16 GB RAM. It is a well balanced device made for 24/7 operations that is relatively cheap (~350-400$ with RAM).
[ ID] Interval Transfer Bitrate Retr[ 5] 0.00-10.00 sec 2.74 GBytes 2.35 Gbits/sec 0 sender[ 5] 0.00-10.01 sec 2.74 GBytes 2.35 Gbits/sec receiver