I might be the only one, but I actually dont like Q power lines that much, and stopped using these....
Yes, they are way easier to "shorten" etc, as you just tie a knot, and thats it.
No sewing and socks etc
But for me (used them many years), they were slower to lay out - because they sort of clinched together - where "normal" lines could you just run out in a jiffy, as they got no resistance
Lines has an extremly high lifetime today, I agree.
On the other hand, it just takes a few unlucky launches, and the line ends will get worn so you HAVE to change lines, or shorten the lines one meter or something.