Cloning Booted RPi's microSD card on Windows PC through Network

Anyone tried doing a multiway shoot out between the different options? dd vs ddz vs tar vs rsysnc?

I suspect they would all hammer a pi but in different ways.

on a related subject:

I have been using Winscp to copy files from my raspberrys to my NAS for a while. One of files is 770MB and it starts out copying at over 5 MBPS but drops to about 150 kbps after a while.

If I use VNC file transfer it stays at over 5 MBPS all the way through.