I ran this test with the WRT using current relased FW as of this date, on 5Ghz, Mixed Mode, WPA2 manual channel 48 on Mac Book Pro OSX 10.9.2 connected LAN cable to a DIR-865L in bridge mode.
ISP Speed package is 50/3:
I belive the chipset on the 865L is Broadcom or Atheros. Not sure at the moment.