I currently run 105 (5700) on my bike. All stock cables from Giant.
I don't have any existing problems but I've read a lot about how great different groups shift and how different cables change the characteristics of a group.

I've read that Gore or Yokozuna are the best cables. I'm considering buying the Yokozuna shifter cable set.

Asking "Will I feel a difference" is silly because I know that has a lot to do with my own abilities and having been around the 41 long enough I'll get 25 different "it depends" answers.

So my real question is: Does upgrading cables typically reduce the amount of adjustment needed over your run of the mill stock cables? Do they typically have less stretch? Given that my cables only have 1000 miles on them, is it even worth the money right now?