The closer you get to the test server the faster your overall speed will be... and on the other side of the coin, the further you are away from remote sites the slower an individual stream will be.
I recently upgraded my DSL from 1500kbps to "between 1500 and 8000kbps" and was disappointed to see that a speed test to Texas USA only showed a marginal increase to about 1700kbps... I just did a speedtest.net test to a local server and it's nearly pushing 6000kbps, which is MUCH better.
In other words... a single stream from TX will go at 1700kbps max, but I could start 3 of them and still have them going at the full 1700kbps each.