I'm on a cable modem with 3mb downstream bandwidth. When it's not bottlenecked on my cable provider's headend, I can get two or three torrents going at 80 KB/s each using PTC. As long as I am judicious with my upstream (allocating 5 k/s upstream to each, for instance, so my 256kb upstream doesn't get maxed out) I can do that and still browse the web with half-decent speeds.