OK why is there even any debate? I just tried rsync’ing a directory with a couple hundred gigs to a USB drive, I had a few gigabytes that weren’t on the USB yet. After several hours there didn’t seem to be any progress. I set up rdist to copy to a different directory (/mnt/usb) on the localhost, and the copy is completed within 5 minutes!
Despite this, when I google around, I find comments going back a decade declaring rsync to be the superior copying tool. hmmm. hours = incomplete vs minutes = success; RDIST winning.