About two years ago, I was considering two new touring bikes, Cannondale or Trek. I inquired of this forum the relative advantages and disadvantages of bar ends shifters vs. STI. I got a lot of good advice. At first I was leaning toward the Trek (with bar ends) but I ended up getting the Cannondale when my local dealer was unwilling to down-size the Trek's stock gearing for a reasonable fee. My old bike (10 years old at the time) had bar end shifters.
For the benifit of those who may now be shopping, I can answer my question definitively: given the choice, bar ends would have been the better choice. STI shifters are convenient and somewhat more efficient as they require less position shifting to change gears. But the STI shifters, combined with the nine-speed cassette, are waaaaaay more finicky than the bar-ends ever were.
On my old bike, I adjusted the bar-end shifters maybe once or twice a year, I changed cables and the rear cassette only once in 10 years; and changed the chain only twice. With the new bike, it seems I will be replacing the chain, cassette, and cables every year, and the shifters require constant adjustment to keep smooth shifting.
Unlike a racing or sport bike, as a touring rider I am concerned first with reliablilty, second with comfort, and third with durability--the STI fails two of these three tests in my experience.