Well it sound like I might be able to help, but as you say it will be interesting to see what happens if I actually start using that sort of bandwidth.

I haven't used bittorrent before, but it seems to be very poor at even using the upload capacity I have made available. I suppose that is because I haven't been able to download much yet. In the last hour there has only been one ten minute block when the upload averaged 600Kbps, the rest of the time it is almost nothing except for the odd spike.