Having lived and worked in Milton Keynes since 1977, I can tell you that the rollout of decent (ie: fast) broadband services is a mess. The new city's grid road system - which was ok when we only needed voice telephony services - isn't helping the spread of fast broadband across the city, but even then the availability of services is patchy and sporadic.
My service, which O2 on a BT line, gives me an average of 2.4 Mbps down and 0.89 Mbps up. This is consistent, and I'm within 2 miles of the Bradwell Abbey exchange "as the crow flies". Unfortunately, the cabled infrastructure means that the actual distance is much more than that due to the fact that trunking runs under the horizontal and vertical grid roads and literally "around the houses" in most cases. Oddly, though, some parts of the city that are close to the Bradwell Abbey exchange are currently enjoying 100 Mbps (which is really annoying!). I've heard of subscribers quite close to me - and further from the exchange - enjoying much higher speeds than me, such as 10 Mbps and higher.
Unfortunately, I can't see a solution to this problem anytime soon, but as a person who works at home as a freelance, I desperately need higher down/up speeds. As for Virgin in Milton Keynes, forget it. I'm sure they'd rather forget that they have an MK operation!
More info on MK broadband see: http://mkbag.org/