Pants

[#1]

BT Speedtester
Download speed achieved during the test was - 869 Kbps
For your connection, the acceptable range of speeds is 400-2000 Kbps.
Additional Information:
Your DSL Connection Rate :2432 Kbps(DOWN-STREAM), 448 Kbps(UP-STREAM)
IP Profile for your line is - 2000 Kbps
I'm not even sure that speed is right.  Browsing is practically impossible. This is more realistic:
(Plusnet Speed test)
Today 19:01  261 kbps (32.6kB/s)  382 kbps (47.8kB/s) 
Currently syncing at 2432.  Gonna try a router reboot.

[#2]

What does this say https://portal.plus.net/my.html?action=stable_rate

[#3]

Estimated line speed:
    Not recorded (service activated before we introduced estimates).
Current line speed:
    2000

[#4]

Another person getting less than 50% of their line speed at peak times - geez these BT network problems really are widespread, and coincidentally affecting an awful lot of PN customers....