Originally Posted by
3alarmer
... I can do double shifts (F+R) with one hand with DT shifters. This is important to me when I am riding on something set up with half step gearing.
Any shifting with down tube shifters effectively requires two hands, since your other hand must remain on the bars while you shift. In contrast, you can make a true one-handed single shift with modern shifters, since your other hand doesn't need to remain on the bars. For example, you could shift with your right hand while reaching for a gel with your left hand. You can't really do that with down tube shifters. And, as pointed out below, double shifts with modern shifters can be done easily while keeping both hands on the bars.