No one including PC Pro has a real answer, removing up to headline speed for technology which is what most (including VM advertise) and the current requirement to give an estimate of actual for a customer might not help.
What was needed was an understanding of up to - which always carried the tag line 'actual speed is dependant on length of line from exchange'.
VM is going to be better that ADSL pretty much always due to the technology implementation, but there are questions about the typical speed Ofcom quote, since it excludes the heaviest users (>30GB a month and the lightest), it is looking at typical users only.
Down to what the public perceive the words 'UP TO' to mean, and the estimate they are given for speed at sign up.