I, truly, dislike down tube shifters! Using them forces one to take his, or her, hands off of the handlebars ever time a shift, up or down, is required. This gobbles up time and effort, while negatively impacting the safety factor. My opinion, of course.

If down tube shifters are so great, why are none being used in serious competition today? If down tube shifters are so great, why is it that not one bicycle manufacturer, today, offers them on a production bike? If down tube shifters are so great, why would any of us vintage bicycle enthusiasts like, or even prefer, Brifters?

The point is, down tube shifters have their place, from a functional point of view. Their place is on a antiquated machine that was competitive in its day, but not because of the down tube shifters. Competitive then only because every other bike, except those sporting stem shifters, were fitted with down tube shifters also.

So, do they offer any practical advantage? Nope, other than the weight saving which probably does not amount to all that much in the long run.