I have been with Sky for broadband normal dsl for over 4 years. In that time i have only switched line rental/voice part of the line from talk talk to BT and now finally Sky for that too. So my broadband provider has not changed. I think you are right tho Sky have reset my line profile. Talk talks equipment when i was with them for voice/line rental gave me same speed as BT did with Sky broadband.
It's ironic that Sky broadband is slowest with them for line rental/voice compared to Talk talk and BT with Sky broadband running through there line.

I get what you say about the engineer changing me to Sky's equipment for line rental could have made my line longer.

Since fibre depends on the distance to the cab not the exchange am i right in thinking this shouldn't affect what speed i end up with on fibre when its activated in up to 2 weeks as Sky said.