Even after forwarding ports it depends heavily on the torrent in particular. Certain ones that are popular will download very quickly, while other ones may have a max download speed of 20KB/s, just because there arent many people seeding.
oh you hit the nail on the head, here... whenever i use a torrent, usually as a way for me and friends to transfer files to each other's computers, but its always soooo slow, never going above 200kbps, and thats with one seeder and one leech