There were some great threads a few years back. I believe they were in related to how they do as shooting line specifically. I dont know all the differences, but I have tried some different types. The white stuff rob allen and mako sells is good. Q-line is ok, but the best/cheapest i've found is zing it. Stretches a little, but super tough!
http://wesspur.com/throw-line/zing-it-throw-line.html