Are you serious? Most Debian ISO mirrors I've used have 10gig connectivity and usually push a gigabit or two fairly easily. BitTorrent is generally a lot slower than that (it's a pretty terrible protocol for connecting you to actually fast peers and getting stuff quickly from them).

I've definitely seen higher speeds with BitTorrent, pretty easily maxing out my gbe nics, but I'm not downloading Debian images specifically with much frequency.