Can someone give me a simple answer to the difference if any. Also, what's the timeline for these ropes? First Spectra , then Dyneema 60, then 75 , then 78, etc...? Any reason to buy Spectra/Spectron if it's available? Seems to me that if the cost is comparable, then one would always buy Dyneema 78 . right? This all came about because I've got to change my outhaul/and cunningham lines.