Your download speed has (almost) nothing to do with your connection speed setting unless you choose modem. In that last case LimeWire doesn't swarm from more than 2 hosts at once. Other than that, your connection speed setting has only minor effects on your downloads. If you are on T3, for example, LimeWire will allow more parallel connections than Cable/DSL, so you can download a little faster - however it's pretty rare that you can download a file from more than 6 hosts at once.