You've just reminded me...........
About a year ago I changed from a BT 2Mbps to a BT 8Mbps service. BT did a line check and told me that I would get up to 6.5Mbps, which seemed OK to me, so I went ahead.
For the first few months I was getting about 6Mbps, but then it dropped to about 5, then 4, with occasional bursts up to 7.6Mbps while they were working on the exchange. These were all displayed on a little icon on the start bar. After that (last October) it went down to 3Mbps which was confirmed by the speedcheck on the Channel 5 Gadget Show website, and has remained there ever since.
Seeing this thread, I've just checked again with these results.
Thinkbroadband.com Download 2.9Mbps Upload 0.37Mbps
Speedtest.net Download 3.36Mbps Upload 0.37Mbps
Gadget Show Download 1.53Mbps Upload No result
Hmm, 8Mbps seems a distant memory!
How far am I from the exchange?...........................85 metres - I could practically hit the d@mned building if I threw my PC hard enough, and, believe me, I have been tempted on occasions!
It's just the thought of trying to explain it to someone in Bangalore that depresses me.
GG