Installation is simple: the router is connected to the box via the RJ45 socket labeled "Internet"
The default IP address is 192.168.0.1, so it's easy not to mix the two networks (NB4 being blocked on the address 192.168.1.1).
There is no need to disable the DHCP server of the NB4: it is the router that takes over for all devices connected to it.
I disconnected the wifi of NB4 and used the same SSID and WPA key on the router: all wireless devices are then connected directly to the router without any re-setting.
You will notice that there are several directional antennas and they are: the orientation setting saves 10 dB, so look after it (see the TP-Link website as needed by searching for "How to improve my speed wireless gold range" ).
It would be possible to let the WiFi of the box with an SSID and a different channel to offer free WiFi to guests separate residential private network.
The router includes many security settings for internet access: I accumulate filtering the NB4 and the router without problem, including with IP-based surveillance cameras.
The phone stays on the NB4.
In use the network is much more reactive with 20 permanently connected devices, the worn WiFi network has improved in the house and the much higher throughput: I 72MB / s over now (the maximum speed in 20 MHz) .
To reach 300 Mb / s there are some subtleties as setting must be 40MHz. In this case, the user would SpeedBoost even reaching 450MB / s.
I preferred the scope, so I disabled this option (40MHz the signal drops more easily with barriers, I could see).
Note that it is possible to adjust the power of the wireless signal to avoid sending more radio waves than necessary.
Obviously, as soon as two devices have 1Gb / s NICs, the router can enjoy the maximum flow rate, and changes life compared to NB4 that do not even respect the 100Mb / s.
My network is not organized in a star but with branches equipped with Ethernet switches, so the limitation to 4 RJ45 ports is not a problem for me.
I have not yet found an inconvenience, although I understand the interface in English can be a problem.
I still have to test the print server (that of NB4 is disastrous), the file server (USB connected hard drive) and the media server.