in my opinion BT homehub 4 isn't as amazing as it claim. yes it has gigabit ethernet, but it was only 1 port, then remaining 3 were 10/100. In terms of features with the hub, it was fine, port forwarding, firewall, etc were basic. wifi setting was basic, and the usb slot... couldnt figure out its use...
I got the BT HH4 anyway, but I am not using it because I prefer using a professional modem only device and connect it to a high end router to manage the data traffic within the LAN.
In terms wifi signal, I hid it away inside a room, and surrounded by 75mm thick cavitaied plasterboard and a firedoor, through the walls at 5m distance, the signal dropped to 80%. In comparison to my ASUS router, placing it at the same place I receive average of 100% signal around -40 RSSI.
Wifi speed of HH4 was fair, 130mbps i remember, but you can get up to 470mbps these days with a decent wireless router.
so HH4 is good if you dont care too much about the device and you just simply want to get online. but if you are planning to use your wifi to full extent, ie. IP security camera, NAS, cloud storage, port forwarding, VOIP, VPN, etc... HH4 isn't up for the job.