Jalpari, It really is a simple case of deciding what you want from the article directory - link juice or traffic. If you want link juice, avoid nofollow directories. If you want traffic only, use the nofollow directories too.
i use no follow directories to get traffic. They are great for getting laser targeted traffic. You wont get increase in PR though. Still the visitor count is worth it
Nofollow article directories are, as most people already said - good, for laser targeted traffic. I love using them. They also rank pretty high in the SERP!
a nofollow link is useless for PR but is good for traffic, as well all references are counted in webmaster tools regardless ther are dofollow or not.
Like people above me have said, no-follow directories aren't going to help your PR but will get you slight traffic.
No follow link are sometimes even better because more people tend to visit your site and pass the info about it to the others. So you get more and more visitors and some new dofollow link.
Author Resource links on ArticleSnatch.com are only nofollow till your account has been reviewed. Authors who submit a few articles can request a review at any time via email or just wait till the team gets to it. This is prevent spam and has been working quite effectively. Questions about the site can be directed to the contact form on the site.
Articlebase is the best example you can submit articles and they tend to rank high in google very very quickly and if you build back links you can push them up even higher. This type of nofollow link is good for traffic but other then traffic i dont like to get nofollow links!