What does this say?
I've found it to be fairly accurate
http://www.productsandservices.bt.com/consumerProducts/displayTopic.do?topicId=25795
Had to check by postocode because it's a Sky line, but it says this:
Between 10.0Mb and 19.5Mb (Estimated speed: 17.0Mb)
The exchange is only 2 streets away.
I'll try that right after I padlock the gates.
{{{{Herman}}}}}