A colleague of mind just moved to UKOnline 8mb broadband service about 3-4 weeks ago. He migrated from another ISP. Minimal downtime. However, on the day the 8MB was supposed to be avtive, tests revealed that his download speeds were less than 1/2 MB. One phone call the following morning and the problem was resolved. So far he is happy.
UK Online is part of EasyNet and and Easynet has installed in certain BT exchanges its own special equipment. where this is so ypu can get the cheapo 512k service.
The rub is not many exhanges have it.
So you must go through the motions of getting UKOliner to check your exchange out and tell you Yea or Nay. From there though its a pretty good tenners worth I only wish my exchange was one of the lucky ones.