While not a PS subscriber, too much like consumers reports.....not always correct test methods etc IMHO......
I do have xls extra as halyards and sheets. I do like the feel, less stretch that staset for not that much more. Along with the ability to color code different parts of the running rigging. IE blue/white for mainsail, red/blue for jibs, green blue for the spin.
Takes a pretty good blow to stretch the main/jib halyards.
One thing you have hit on is that much of choosing, in the end, is application and opinion. For example, Stay Set-X:
* A slight improvement in stretch control, but only about 25%, as I recall.
* A big increase in tangles. Too stiff and doesn't coil as well.
* Does not run through blocks as well.
* Not nearly as durable as most high modulus lines, and thus not a good value over time in some applications (and I am a cheap skate--I use both sorts of line, each where it is the best value).
Some of this could be reduced to numbers, but not all of it.
Some people like a rope with a stiff hand.
and so PS uses honest reviewers that express honest opinions. With many products there really is no "best" because of variations in needs.
Those items that lend themselves to laboratory-like testing are tested in that manner. Sometimes there are no ASTM or other recognized tests. Sometimes exhaustive testing would be crushingly expensive. They say what they did and report what happened. Given the lack of advertising to pay for it all and the limited circulation (way smaller than CR!) I think they do a lot.
No, I don't agree with all of it. I write in occasionally. But I respect anyone that runs tests squarely and reports results honestly.
Regarding stretch and halyards, it depends on the boat. My current boat uses Stay-Set and that's fine. My last boat I converted from wire to a 2-part purchase with a Kevlar line. Worked fine. After that wore out (10 years!), I went to Stay-Set X, which was a failure; far to stretchy and more prone to tangle. Later I re-tasked the halyard for other things and still did not care for how it handled. Personally (personal opinion) I think Stay-Set X is a pointless product, while Stay-Set and their high-mod lines are great.