BT Infinity faster than Sky

[#1]

Last a BT advert came on and it said Infinity is faster than Sky.
How is BT Infinity faster than Sky as I thought all ISPs used the BT network and same copper/fibre links?
Raises the question how do PlusNet compare with these two?

[#2]

http://www.thinkbroadband.com/news/7301-broadband-speed-test-results-for-december-2015.html

[#3]

Interesting I need to change to BT and not Sky then at end of my contract.

[#4]

I really suggest that you think a bit more about that as the speed for an individual fibre connection will essentially be the same for all providers

[#5]

The headline connection speed will be the same but that's not the only thing that affects end-user speed.
There is also:
* Sky backhaul from your exchange to their network.
* Sky's core/national network.
* Sky's routers and ancillary servers (eg; DNS).
* Sky's interconnects and peering arrangements with other ISPs.
In general I'd expect most differences in the first item. Depending where you live that could go either way. BT aren't usually too bad at maintaining capacity. In the past Sky have sometimes fumbled in this area. Sky at its worst is a lot worse than BT at handling backhaul congestion.
But except when things go really wrong most people are unlikely to see that much difference from one FTTC based provider to another. I would trust BT slightly more to fix capacity related issues because it has other ISPs bleating at it whereas for Sky it's just customers and Sky is quite capable of ignoring them.