Re: New England Ropes Synthetic lifelines?!?!
I replaced my coated wire with Dyneema a couple of years ago after noticing some cracks in the swaging and some corrosion through the coating. I did not want to worry about corrosion and swages again. They are light, strong, have no meathooks, and are a see-able quantity. There's no guessing about whether swages are good or not. The best solution would probably be eye-spliced bare wire. Brion Toss has a good method of splicing 1 x 19 wire in his book and a demonstration online. Brent is right about wire being tougher. You aren't going to slit it with a sharp edge. That's my main worry about the Dyneema. Once I become proficient at doing wire splices, I may start replacing all my swaged fittings, swageless and swaged, with splices.
As far as length of Dyneema lifelines goes, I would leave 6" and use lashing. That's what I did and it has worked out well. The lashing method allows adjustment for stretch. Dyneema does stretch over time. My 6" is down to about 5" now, maybe a little less. Another plus for Dyneema is being able to easily wrap them up and stow them in a locker. I spliced around 5/16" shackles at the gate ends. The shackles act as stops so that the gates, when secured put tension on the run.
Alberg 35: With a philosophical flourish Cato throws himself upon his sword; I quietly take to the ship.