I wouldn't count on article directory link juice anymore so much - they're corrupting the web already
But for traffic,yeah, they do work. Search some 3-4 word longtails and you'll almost always find an ezine entry on the first page. So, IMO a good way is to come up with 10-30 long tails related to your topic, verify them with google adwords keyword tool that they get hits, and write/outsource an article for each of them -> hit ezine -> get visitors.
Also a hub is very easy to promote to first page for longtails.. optimize, social bookmark, link from ezine -> high ranking.
Just my thoughts.