When I changed cables this past spring I put on "noodles" on the shift cables of my Cannondale. I am not sure if I would do it again or not. It does give more clearance for my bar bag, but I sometimes (not always) think that the shifting isn't quite as good. But that may just be me on those days. I do think if you're riding without the bar bag, they look a bit funny, but so what.
My wife and I have had our Cannondales for nearly 4 years, and use them for rec riding and loaded touring. Last year and this year we did trips of about 1600 km (each year) and have done a bunch of shorter tours. The shifters have never created a problem. Our bikes use Tiagra, ranked pretty low in the Shimano world, so I would expect 105's or up to be even more reliable. Even Adventure Cycling has said that anticipated reliabilty problems with STI's have not developed. I like the STI's too much to go to barends because one time in 5 years or more I lose a day or two cause a shifter strips out.