I jsut got a set a week ago and I am as impressed as one can be with cables. They are very light, having generic cables and housing before hand I was shocked at how light they were. Unlike Nokons, the I-links are all linked together, so you don't have to worry about spilling them or waste time putting them on one by one and have them all slip off accidentally after the last one. The inner liner feels nice, but my only gripe is that it kinks really easily if outside the housing, especially since it is coiled when packaged (no other way to really do it though). Luckily the kinks were in places where it didn't really matter to me since it was cut off.
I can't speak for my shifting performance right now since my ancient Ultegra group isn't as smooth as it used to be, Shifting in the front is definitely smoother, rear feels about the same. Braking on the other hand is amazing, I feel like more power is going to the brakes.
Get them, you won't regret it. They look great, are light and work flawlessly, what more can you ask for?
I have heard complains about it though. From people using Full suspension bikes that is. That it rattles onto the frame too much producing an irritating sound. I dunno perhaps they went on trail and did alot of ups and down and bumps. But for my mtb, i was running on slicks on the road. So that'll be a different story.
I hope this helps (:
run full housing and zip ties. Plenty of rubber covers are given to you that you should be able to cover all parts of the frame where you cannot use zip ties.