How fast you are makes no difference. What really counts is how much time you waste. I like the speedlines because they let me keep working instead of waiting for the groundies to return a rope to me. That, and you can set the lines for quite a few cuts, then begin repositioning while they clean up the mess you sent them.
I really like how they drop all the longer limbs butt-first, pointing at the chipper, out of the drop zone. Sometimes I alternate speedlines and just dropping stuff so that none of the work zones gets all bound up with too many guys or branches.