String loop........always and forever.
With a string loop, you get zero string torque (unless your doing something really wrong), a more direct line of pull behind the arrow (helps with nock travel), no nock pinch, no serving wear, more consistency and a cleaner release. They are generally lighter than most off the string nock set ups........and with many of today's string loop specific releases you don't have to give up any draw length to maintain a proper anchor.
Other than that I see no advantages over shooting off the string.
