I'm lucky enough to live in one of the cities with gigabit internet. I ran a speedtest after I got connected and saw a consistent max of 140mbps over a wired connection. From the wall, I was getting roughly 850mbps. LAN transfer speeds are fine through the AC66U- I can max out the gigabit lan no problem.
I went back to stock firmware and ran another speedtests. I saw about the same near-gigabit speeds as when I was directly wired, so tomato (or some setting) was the bottleneck. I did notice the system load on the control panel went > 1 during each test. I was not using a VPN or QoS. Anyone have any ideas why the router CPU was bottlenecking?