FWIW, I've been riding my road bike since late 2002, and while I'm comfortable taking my left hand off the bars (to get a drink, signal a turn, whatever), I'm still not comfortable holding the bar with my left hand and taking my right hand off for more than a split second. (I'm right-handed.) And I don't think I would like those bar end shifters at all.

Also, last year I had a very short riser stem put on my bike and I didn't notice any difference in handling or twitchiness (sp?) with the new stem. What I did notice was that my shoulders are no longer hunched all the time and most of my neck pains have gone away.