As a hitch and a binder, I generally prefer the Bag Knot (ABOK #1244, #1674) over the Groundline (ABOK #1243) and the popular Constrictor (ABOK #1249). As a hitch, the Bag Knot is more resistant to jostling and generally holds more securely. I have also found the Bag Knot to be a more secure binder overall.
The Groundline is easier to untie, which is unimportant because the Bag Knot doesn't jam. The Groundline tends to fall apart with excessive jostling. For whatever reason, the Groundline gets its own Wikipedia entry, while the Bag Knot is hidden within a group of Miller's Knots. Go figure.http://en.wikipedia.org/wiki/Ground-line_hitchhttp://en.wikipedia.org/wiki/Miller%27s_knot
The Constrictor has that temperamental top strand that has to stay in the right position for the Constrictor to work properly. I would not consider using the Constrictor as a hitch.
Bag Knot (ABOK #1244, #1674)
Groundline (ABOK #1243, #1676)
Constrictor (ABOK #1249)