Not sure about Azureus, but I have found that with uTorrent that if I have Firefox open and on a site my download speeds go up a good bit.
Your download speed will be different than most. It depends a lot on what your connection speeds are. I have 1.5M DSL, and I can get up to 150 on something with a lot of seeds (like Knoppix). I usually run in the 50-75 range.