Ultegra 6700 shifting badly. Could it be...?

Why won't my bike shift well?
New chain? Check
New cassette? Check.
Adjusted with love and care? Check.
What of what could cause the normally-delightful Ultegra 6700 to shift like ... like something that doesn't shift well?

I'm getting ready for some long rides and thought I should do the new cable thing. I got Gore Ride-on brake and shift cables. Son of a gun, when the right shifter cable came out is was frayed as all get out.

New cables = wonderful shifting. And oh, what a pain if it had broken in the middle of nowhere.

I'd had a similar issue with my 6600 Ultegra brake/shifters. The end actually came off and took forever to dig out. I wonder if this is a design problem, that perhaps they route the cable through too may turns. I don't think this should have happened after only 4500 miles.

UPDATE: See this post