Ok I see the point of view from the thread you directed me to. My question is, is the gnutella net mostly populated with clients that "swarm?" If not then modem users are mostly useless for uploads. If most clients do not swarm then modem users would better serve the net by connecting, finding something to d/l, disconnecting while a D/L is ACTIVE and allowing one upload. After the D/L is complete connect back to the net.
As far as having to wait for files you will never have more open slots than filled because our "wants" are unlimited while the supply is limited.