said by Matt3:If it can, any router that has 16MB of RAM would likely be just as capable, but you may need to dump a custom firmware on there to tweak it.
this is mostly correct. there is some additional issues that will arise when you are working with half-open connections, switching, and state tracking of existing tcp connections. all of that requires ram and processing power. because different processors and hardware switching asics are installed in different devices are not all created equal, a large parity exists between a lot of consumer routers and their soho brethren.
in all honesty, if you are looking to run a ton of torrents, you would probably benefit from rolling your own solution of pfsense/m0n0wall/bsd on an alix or soekris board. for the amount of money you'd spend on a "good" router, you're going to approach the price of rolling it yourself. the best part is, you can use your existing router as a wap by disabling dhcp and hooking it into the lan ports.
q.