Originally Posted by godspiral
Stem shifting is really convenient when slowing down up a climb, and is probably the only important occasion where easy and fast shifting is important in a commuting setting.
This is actually the argument for bar end shifters. They allow you to move your hand outwards and keep a hand on the outer side of the bars which is much more stable going slow. I have a hard time riding slow with my hands at the stem or center of the bars. Bar-end shifters were first developed for touring bikes where stability at a low speed (and next to a big cliff) was critical.