If you have a different ISP you should check which settings you need to change here: http://www.linksys.com/gb/support-article?articleNum=187899
Most VDSL capable ISP packages (a.k.a "fibre") use PPPoE which requires you to enter a username and password in order for your internet to work, 'Talktalk' uses "IPoE" instead which just automatically works which is nice. Some ISP's may initially refuse to give you these details but you can often find out the details by googling them. Uk ISP "BT" actually blocks non-BT modems either immediately or even up to 9 months later. You may need to change the Linksys' MAC address to the one on the back of your BT homehub router to get it to work using the "MAC address clone" option shown in the screenshot above. So don't throw away or sell your BT router as you can't both use the same MAC address.
This router appears to be working well so far, you can see the names of devices and their mac addresses connected via LAN or wireless too using the "DHCP client table" button which opens a new window and shows this:
I uploaded screenshots of the whole of the web interface here: http://setuprouter.com/router/linksys/x6200/screenshots.htm