I'm actually in Manchester and using SpeedTest.net on the 2 servers the ping is still better going to Maidenhead than just going up the road. Not that I would know what to do with a ping if I saw one.
Having now read so many of these 'speed' threads I understand that these test sites are not overly accurate at the best of times as far as speeds go so I have no idea whether they are any more accurate recording the mystic ping.