I posted earlier about why it's a bonus if the directory you're submitting your articles to approves them fairly quickly.
A bit more on that subject: I recently found another directory that looked pretty good. It's called Uber Articles, and it has a PR of 4.
I submitted an article there several days back, but it's still stuck on pending. I looked in the dashboard, and saw that there were literally thousands of articles marked with that status. So, if those figures are accurate it seems to have a very big backlog. I decided to give it a miss and submit that particular article somewhere else. So, I'd suggest that that's one to avoid if you value quick approval highly.