I have to admit I don't know much about the other types of suspension you mentioned...but here are the reasons I settled on this style.
easy easy easy
By folding the dynaglide in halfe and larks heading it to the whipping i'm able to avoid knots...and splicing.
adjustability...once I have the sag set to where I need it...I can adjust the height of the foot end in just seconds without having to make any changes to any hardware.
I dont have to touch the marlin spike hitch...or the elephant trunks...and I dont mess up the sag in the process.
You see...what I found difficult of conventional suspension systems is that any change I make on one side...has to be compensated for a bit on the other side...difficult for noobies...and I'm sure there have been some people who have gotten frustrated and turned off by it.
Am I making sense?
I would love to see some forum members try it out