Luke wrote:

In short, bar-end shifters emphasize durability, versatility (those
with indexed and friction modes) and economy; they're more suited to
the demands of touring or commuting. I'm not sure if the 520 is the
only 'modern'(?) bike equipped with bar-end shifters, but almost any
bike with drop bars is a candidate - and with the addition of Pauls
Thumbies, MTBs too can be so equipped.

Rivendell has bar-end shifter on the Romulus. Personally I like the
brifters on a mountain bike, but on a road bike I'd be happier with down
tube shifters than bar-ends. If I have to move my hand to shift anyway,
then why not go for the true retro-grouch location of shifters.