They all mess you about with speeds what ever provider. Most providers rent bandwidth off BT as most phone lines are BT lines and They only rent so much Bandwidth so as more people sign up theres more people using up that bandwidth making each user get less and less.It's not just about how far you are away from the exchange it's how many people are sucking the power out the line at the same time and how the provider is not buying extra bandwidth quick enough to keep up with the amount of extra users.