Is there anything I can do about this? Will bt/ Orange do anything about it? Any idea what the impact of this oddity is? I live about 0.5 mile by road from the exchange if that helps any. Seems odd I have ADSL2+ and such poor speeds.

Usually it means it is a router issue, i.e. you cannot trust the figures it is showing

Time to try modem on another line and see how it reports data and compare it to a known good router

Dunno! just can't trust attenuation figures on any of your routers. So can't say what your expected speed should be.

Get Orange to send you a Brighrbox router as yours is faulty.

Any idea how I do this? All I get is hours on the phone to go through their same script and "it must be your end as we can't see anything wrong" even though is was connected directly to the master socket with no extensions.

I have also been having intermittent massive slowdown issues. Generally a reboot of the livebox fixes it. Orange's response was "well just reboot it" . They even tried to tell me that the ADSL filters get blocked if you use the internet a lot - just like a fuel filter on the car! Therefore I should call every 6 months for them to send me a new one. !