I think bittorent is much better with regards to trading and sharing. You can always make a torrent of your Xbox isos and upload them to a public tracker and then give the link to that torrent to the person you want to trade that ISO with.
Also, just to make sure that there are no unwanted leechers sucking your bandwidth, you can always name your torrent something else (for example "my grandmother's wedding anniversary") and give the link to the person you wanna trade. Then he'll be the only guy downloading from you and getting MAX of your bandwidth. Pretty Simple
Also, this way there is absolutely no question of broken uploads so you won't have to upload your files 5+ times
