You might be able to eek out a bit more speed by looking at some tweaks for your system as Frostbite suggested. I are smart. I guess it's just a lingering misperception from the voice modem days, but the CO distance has no measurable impact on your throughput or latency. Unless you're on the edge of the rated distance for your line speed and seeing packet loss to your gateway as a result of bit errors, it doesn't figure in. To a lay-person though it probably does seem like useful information to include.
More distance usually means less quality.
The second problem is just that the frequency and modulation the DSL signal uses will just not go all that far. That is where being at the edge of the distance limits comes into play. There is a direct coralation between throughput and distance. So, you can see why people see distance as a factor in their quality of service. I are smart.