This is because in order to go to the router's Web interface, a connected client needs to have an IP address in the same range as that of the router. Since the router's default IP is 192.168.0.254, you will have to manually change a connected client's IP to be 192.168.0.x, with x being anything between 1 and 253, before you can access the router's interface. After that, once you have configured the Nano to work as a router, you'll likely need to manually change the client's network adapter to obtain the IP address automatically. In the rare case that the existing wired network shares the same address range, you've lucked out and won't have to change the client's IP address before accessing the router's Web interface.
Now if the above paragraph sounds complicated, that's because manually changing the IP address is a confusing process for most home users, and the Nano could spare them this if its default function were set to be working as a router, like many other multiple-role routers on the market.
Other than this design hiccup, I found the Nano offers a lot for a router so tiny. You can use its Web interface, of which the default username and password are both admin, to customize its long list of common features, including Quality of Service (QoS), port forwarding, MAC address and IP binding, dynamic DNS, and so on. I did find that it lacks support for IPv6, however, so I hope IPv6 support will be added via new firmware in the future.
I didn't expect much from the Nano considering its size, but the router performed very well, both as a router and access point.
When used at close range (15 feet), it registered about 23Mbps, which was more than fast enough to share a connection to the Internet. When I increased this range to 100 feet, the data rate dropped to about 9Mbps. Now that is very slow, but I was actually impressed that the router's range could reach 100 feet. In fact it could reach slightly farther than that, but I found that it's best used within 30 to 75 feet, which is about the right range for a hotel room.
I also tried the Nano as a media bridge and a range extender and in both cased it worked as intended. It's not exactly easy to set it up for these roles, however, and the device is really best used as an access point or a router, rather than anything else.
(Longer bars indicate better performance)
For those who can get past its potentially tricky initial setup (as a router), or just need a plug-and-play access point, the TP-Link 150Mbps Wireless N Nano Router would be a handy device to carry in your luggage.