After I broke a spoke on the rear wheel on my commuter bike I figured when I had that fixed I'd get new shifter cables as well. I had some Jagwire cables and was just too worried to install them myself. I had the The Wheel Peddler do it. After watching I'm glad I did. It seems they're a bit different than the 1975 version I'd last installed. They're Teflon and have some sort of magic sleeve and weird ferrels.
The upside is my bike shifts better than it has in years.