My wife and I have Cannondale T800's, and while we haven't used bar-ends, we wouldn't be in a hurry to switch to them. Our biles came with Tiagra STI-lower end. They worked great for over 5 years, then seemed to be getting a bit sloppy, so we upgraded to Ultegra's. As we, and I think most tourers, spend most time with hands on the hoods, not in the drops, the shifters are always handy. And still handy to shift when in the drops too. I think the reliability thing is really a small thing nowadays. The only time I've been riding with anyone, and had any shifter fail was years ago, and it was a MTB Gripshift.
I believe that you are a lot more likely to use your gears properly, if you don't have to think about moving your hands off the bar every time you want to shift. As for keeping them in adjustment-we do a three week tour every year, and have never needed to do more than turn the cable adjusters half a turn or so.I have nothing against barends, I just wouldn't bother putting them on my bike.