@MIGuy I'm not Mark, however, I am not a big Sta-Set fan, especially Sta-Set X.
Sta-Set was one of the early low stretch Dacron lines, a big improvement over twisted and double braid. For that we should all be thankful. However, it is not without its shortcomings, especially with Sta-Set X. The lines tend to be stiff and prone to hockles. Some racers refer to them as a$$hole knots because they, well look like... And they jam in cleats and blocks always at an inopportune time.
Both lines are difficult to splice, especially Sta-Set X because of the very tight weave on the cover. The innovation with Sta-Set X was a parallel core construction. The fibers in the core run the length of the line and are not woven or braided. This reduces the length of the fibers in any given length of line thus reducing stretch. Braided or woven lines stretch more because as tension increases the fibers begin to straighten out and become more parallel, effectively making the line longer. Think of the Chinese finger trap, as the trap is pulled the fibers straighten, the diameter become smaller, and the trap lengthen. Same thing happens to the fibers in the core of any line. This can be a problem with line stoppers as the diameter decreases, the line slips. I ended up a brand new main halyard because under a lot of tension it was slipping. The line was ⅜" NER VPC a very good line for halyards. Increased the size to 7/16" and the clutches held.
Low stretch lines are not as important for sheets for 2 main reasons. When the sheet is under the greatest tension (going to weather) only a very short section of line is under tension, thus even a 2% stretch only amounts to an inch or so of stretch. Second, sheets, especially jib sheets are easy to trim and any stretch can be trimmed out.
Samson Trophy Braid is a nice jib sheet line, if I was replacing my jib sheets, I'd go with them. They have an easy hand, grip the winch well, and are less expensive.