historically, rumour has it that messengers in london used them as they were more comfortable than track bars and offered more hand positions...
this was when they were all riding fixie funny bikes...
after riding both lopro and drops (including track specific), i'd err towards lopros for messenger work/day to day riding and track drops for stylee. innit.
my favorites are the dark grey mavics. my lady swears by nitto 19's (not the other ones which are poo). some of my german friends like syntace, whilst profile have been very popular in london for the3 last few years.
then again, what looks best on ya iron?