Thought I'd throw my invention into the discussion. Calling it the Knotty Not just for fun.
It's a cut off section of aluminum tent stake with a 90 degree bend at each end. In addition to the easy adjustment of the tail, which the single ring approach affords, with the Knotty Not you can easily remove the whole device from the line to quickly move it to another section for large scale adjustments.
The downside is since it's not captured on the suspension line, it can easily be lost.
Here's a short video.