What about the other point I mentioned. DSL speed is affected by distance from the nearest major relay point/station of the telecommunications provider. I'm getting about 96% (1440/1500) of the rated download speed, and that's good. What are you getting?
Also, I'd rather get a consistent 1440 kbps than a service that sometimes gives me 1817 kbps but then may be a low as 196 kbps at other times, especially if the frequency of slower speeds is rather common.