With ezine I have submitted over 30 articles and have so far had 17 clicks on my links in all them articles put together. Some people say it's good for traffic, but I guess it's just not for me with the traffic. I still use it though as people us it to re-publish my articles which is what I want the end result to be.
From my little research what I found is, articles are not for quick traffic. It work more like as long term traffic building policy. Building links and indeed make the SE index and rank your site higher for certain keywords on your articles is what we will get by it.
I have approx 90 of my articles on Ezine Articles and i have found it to be a very valid and helpful tool in promoting my company., i get a lot of clicks through them, and my articles get to be downloaded and distributed by other site owners, newsletters etc etc so in my opinion, highly recommended.
When I started using ezine I didn't think much of it as I wasn't seeing immediate results... then when I wasn't paying attention to it at all, like a stealth bomber the backlinks and traffic suddenly increased. I then went back and started uploading articles again. It's a long term strategy.