Your thread relates to Sky broadband and it is to this I will respond.
Sky is merely a broadband reseller and as such is reliant on the BT network for their service offering. This means that they are no better or worse than any other reseller until you look at other factors.
Since they rely on BT, they must adhere to BT's capabilities and not make sweeping claims about what they can and cannot provide. If they could provide everything through the dish, then they would control the speed and the service, but they don't so they can't.
Sky's 10 million customers are TV customers - they are most certainly NOT broadband clients and you'd do well not to mix data for whatever reason you have here.
Sky has a bad press for a number of reasons and they have their 'good' sides as well as their 'bad' but in general I keep to the same rule as I have done for years. If you don't own the cable between the house and the exchange, then you are the weakest link and can only ever be an "also ran". Sky Broadband is an "also ran" and should be treated as such along with the others of their ilk.
SHARK!
For every positive action, there's an equal and opposite government plan.