Good cables improve shifting and last longer. Upgrading your cables is one of the cheapest ways to improve your bike. I have used these Jagwire cables for years and have never been disappointed.
Used this with Sram Rival 10 speed shifters and 11 speed rear Derailleur, for a longer wheel base comfort bike. Plenty long and the .1mm difference over the other leading brand did seem to make it easier to thread through the shifter housings. Can't say if the pre-stretching made a difference as I am frequently changing wheels and fine tuning the dialing in, though I imagine it must help.
I had used these cables a lot for my Shimano equipped bicycle, and they worked very well, in terms of durability and operation. So, I decided to purchase them for my Campy setup, and that was a different story. I tried two cables and both of them brokefrayed near the barrel connection. There is probably a difference in construction compared to a Campy cable and housing combo.