I have recently begun using my petzel ascenders in conjunction with a biner as my suspension . The ascenders bite into the ropes at both ends (see pictures) and are easily adjustable. Simply tie a figure8 in the end of your line , run it around the tree or through your webbing and connect to the ascender which hangs on your line. When the line is tight it pulls the biner backwards into the smaller part of the groove in the ascender and pinches the line holding every thing tight. By pushing on the biner it slides forward with no resistance to tighten your hang, and when loosening simply slide biner forward and lift rope up and away from teeth. Not for everyone I'm sure but just another option maybe overlooked and extremely light weight as well.