I see a wide range of download speeds, from 0KBS up to 120KBS, so I know that the slowdown is on the other end of those low speeds. If the source has a relatively low speed connection, yet has too large a number of upload slots specified, the transmission speed is going to be slow, no matter how fast the downloader's connection may be. What surprises me is the frequency that someone with a low speed connection goes after the largest files I am sharing!
It would be nice if there were some kind of limit on how large a file one could download, depending on the speed of their own connection. The limit calculated so that the maximum uninhibitted download time would be an hour, for instance.