I think this is the earlier thread that I was basing my previous mobilespeedtest.com comments on...
http://forum.ppcgeeks.com/showthread.php?t=88632
However, have a read and you''ll see that there were lots of inconsistent results from all kinds of testing sites.
You may be better off using different testing sites, at different times of the day, and coming up with an average. Too many factors to just use one site at one specific time. There are also issues with using anything other than PIE for testing???