I'm on something crappy like 1.5M/256k and 5 accounts runs fine, my connection becomes a problem when I try and run 10+.
The latency is a bit of an annoyance, your clones will follow at a longer distance during your servers peak hours - but it isn't anything that will ruin your play.

+1 Keyclone

*edit* My latency didn't go up, 1 client to 5.