Real line speeds of 57, but Plusnet says I'm getting 78

[#1]

New customer, when I had the line installed (switching from VM) the engineer said the line quality was good and I should expect speeds in the 70s.
Started off in the mid-50s which I expected due to line training, but it's been a few weeks now and I'm still stuck there.
Oddly, today I received an email from Plusnet saying my current speed is 78 when it isn't.
Any thoughts?
Duncan

[#2]

Testing wired or wireless?

[#3]

Because when Plusnet provisioned you they applied the default  profile based on the 80Mb/s product and this will remain until a delta report is received and at that time it will match the BT IP profile

[#4]

Thanks for the reply Oldjim.
I assume that means that once the delta is received the reported current line speed (including via the link in your signature) will match what I'm actually getting.
Seems strange that Plusnet's method of reporting line speed just gives a theoretical number and not the actual speed.
Duncan

[#5]

Agreed  it is odd but that is the way it is set up and is a hang over from the time of MaxDSL when the IP profile wasn't a direct multiple of the sync speed
I wouldn't bother too much about the Plusnet number being higher it is when it is the other way round that people get twitchy