I think that a 1.0 ratio is not enough. The ideal to me is 2.0 or above. Because at 1.0 you only replace another seeder as you leave the swarn (the network). At 2.0 you garantee that you replaced your seed and added another seed to the swarn. This allows the torrent seeds to increase well.
And we always have to compensate for the newbies that leave before seeding.
