I don't know if you checked already, but you can check the range and speed compared to other routers from the reviews and database posted by this website.Can anyone compare the performance of the RT-N66U with the RT-N56U? I think that would be very interesting.
Thanks...
For wireless range and speed you can check 2.4ghz here:
http://www.smallnetbuilder.com/lanwan/router-charts/bar/58-2_4-ghz-dn
Then highlight a few that you want to compare by checking the box next to each name, and clicking the "Performance vs Location" button at the top. You can also change the "benchmark" to view at the top of the screen.