My Home is 180 meters from the BT cabinet (82 Hunslet Exchange). It's in a vast new housing estate, and there 2 large Fibre optic units/boxes linked to the cabinet. My current download speed estimates from the checker are 80/66.9 Mb/s (clean) and 80/56.9 Mb/s (impacted).
When FTTC was installed in March 2014, the max download test speed was 64 Mb/s. Due to power disconnections & crosstalk (DLM activated) this speed gradually reduced to as low as 48 Mb/s. So I complained to TalkTalk who sent an open reach engineer out. He confirmed that there was a problem at the cabinet. He said the cabinet was full of pairs causing excessive wideband noise (crosstalk) and he had to move the pairs to a new pipe to resolve the issue.
My Downstream Line Rate is now 77.8 Mb/s & 74.9 Mb/s is the speed test result - it's been stable for the last 60 days.
It's obvious crosstalk is an increasing problem and BT should stop finding excuses for not implementing crosstalk.
Speed Test Result
Vectoring to reduce Crosstalk