I've held off reviewing the Asus RT-N66U Dark Knight Double 450Mbps N Router until now due to some known bugs in earlier versions of its firmware. The latest, version 126.96.36.199.108, is still, well, a little buggy, but fortunately not seriously enough to keep the router from being an excellent networking device.
Being the first N900 router from Asus, the RT-N66U offers stellar performance on the 5GHz band and a vast number of features. The router also has great wireless range and was very stable in my testing. With two USB ports it has more to offer than other USB-enabled routers, and it was very fast when coupled with a storage device.
The RT-N66U isn't perfect, however. Performance on the 2.4GHz band was slower than I expected, and the router's USB ports lack support for the latest USB 3.0 standard. Nonetheless, if you're looking for a top-notch router for your home or even a small office, the RT-N66U is one of the best on the market, especially considering that its street price is lower than that of the Linksys E4200v2 from Cisco.
Design and ease of use
The RT-N66U looks similar to its predecessor, the RT-N56U, with a sleek casing that more resembles a jewelry box than a networking device. The RT-N66U, however, can't disguise its true nature due the external-antenna design, with three of them sticking up from the back. These antennas are detachable but you do need them in place for the router to work.
Also on the back, you'll find four LAN ports and one WAN port. All of these ports are Gigabit Ethernet, meaning you'll also be able to get a fast wired network if you're not interested in wireless. Near these ports are the Wi-Fi Protected Setup (WPS) button, the reset button, two USB 2.0 ports, the power button, and a tiny power port. While that may seem to be a lot of things on the router's back, items are well-distributed, so it's less cluttered than you would imagine. Still, it would be a lot better if a few items were moved to the front or the sides of the router, where there are no buttons at all.
On the front, the router has an array of LED lights that show the statuses of the ports on the back, the connection to the Internet, the USB ports, and the wireless networks.
The RT-N66U comes with four rubber feet to make it stay put on a surface, but it's also wall-mountable. It comes with a separate base -- which, interestingly, I couldn't attach to the router until I broke a little piece of plastic off of it -- for keeping it in a vertical position. (That little piece is probably there to keep the base from falling off, but it's just too long, making it almost impossible to attach the base to the router.)
The router comes with a CD that contains setup software that walks you though every single step of how to set it up, so it should be very easy for home users. Savvy users can skip the CD and use the router's Web interface to set it up by pointing a connected computer's browser to 192.168.1.1, which is the router's default IP address. The first time you go there, the interface will greet you with a Web-based wizard with steps similar to those of the desktop setup software.
Either way, you won't have any problem getting the router up and running. I myself was able to do that in less than 10 minutes, including opening the box.
The RT-N66U is an N900 true dual-band router, meaning that both of its bands (5GHz and 2.4GHz) can offer up to 450Mbps, currently the fastest speed of the Wireless-N standard. In order to enjoy this higher speed, your Wi-Fi client also has to support the 450Mbps standard (also known as the 3x3 standard), which most of them don't. Nonetheless, the router works with all existing Wi-Fi clients, including those made for pre-N wireless standards.
To make sure the router offers maximum compatibility, you'll need to change the settings of its wireless networks to Auto and the encryption methods to support both AES and TKIP methods. To do this you will need to use the Web interface, which also allows you to access to all of the router's features.
And the RT-N66U's Web interface is great: well-organized, responsive, and reasonably simple. There are three major parts of the interface that you can access from the left part of the page. The top part is the setup wizard mentioned above, the middle is for General items, and the bottom is the Advanced Settings.