John Paul, I posted this one here instead of Treeebuzz!
I've read those results a while ago. I have one point to raise about the validity of the test. One of the general conclusions you should walk away with is that it's better to stick with good-ole nylon, and leave the vectran and technora at home.
In a kernamantle rope (all nylon) much of the strength is in the core, but the cover helps, too. For the xmission testing, they compared a 7mm nylon cord to the vectran/technora cordellette cords. It is the cover, not the vectran/technora itself that makes the rope so stiff. The same can be seen in lines that we arborists are more familiar with like t-900 and ultratech.
Due to the high strengths of these cordellettes, the manufacturers made them in a smaller diameter and usually add a very tightly woven cover to add chafe protection.
(for those of you not familiar with the rock climber's use of a cordellette, it is often hung over the edge of a rock face with a climbing line dangling from it. This is what catches the climber when she/he falls. These cordellettes need to be reasonably tough so theat they do not break while being weighted over sharp edges.)
So now it turns out they were comparing a 7mm nlyon to a 5mm high tech line. The nylon has an advantage off the bat, just because it's bigger!
But wait, it get's better. In these high tech lines, the cover is there not for strength, but for protection from chafing, the sun, and other things that might want to destroy the vectran
So in these lines, all the strength is in the core. To give the point, take what the xmission testers wrote about the knotted breaking of some of these high tech lines
...For a double fisherman's knot, Gemini and Titan share an interesting failure mode. The sheath breaks at the knot and the slippery core unties, pulling through the sheath...
Both the 5mm Sterling Vectran and the 5mm Gemini (technora) cord have cores of about 3mm, an eight of an inch. The xmission testers were testing a 7mm nylon to other lines about half the size, only 3mm! The vectrans and technoras broke around where they should for a line of such small diameter.
It should be stated that high-modulus lines do not lend themselves well to knotting. These same diameter lines would break much higher if they were spliced, rather than knotted.
I don't want to discredit the work they've done. They have provided some good hard scientific facts. But keep in mind that these facts are not blanket statements. I fully disagree with them when they say
...Nylon cord and webbing may be the best of all. There are applications where one should shy away from the high-modulus lines. But there are other places where you just can't beat the vectrans and technoras!
Climb safe!
love
nick