Hubpage is a web 2.0 property whereas Ezine is an article directory.
Hubpage - you can earn money from adsense and there hubpage ad program by writing quality articles, as well as, get a link back to your blog. Now, its hard to get accepted.
Ezine - In ezine you can submit articles with your blog link below the article. This was very effective to get strong backlinks from ezine before Google update,now it dont work anymore.
Well, HubPages does not review articles prior to publication. This means that there is the possibility of more "spam" or other "junk" articles being published. Since the web is an array of connections, the quality articles written by an author may be lumped together with lower quality articles. However, HubPages does police its site, so the proliferation of junk or link loaded articles can be checked, although there is no guarantee that such measures will be sufficient. However, pre-review of articles is no guarantee of quality either. I hope it will help you to choose a best one from both of you.
Both has different importance. With the hub pages you can expect an average traffic, it may change now and then. With Ezine, of course it can bring a lot of traffic. But it may take time. As your post on Ezine gets traffic and Google started prioritize it on the SE. It can bring you a massive traffic sometimes and a few at the other side.
Ezine is fantastic article directory by now and they don't compromize with the quality of the article.
I heard about Hubpages years ago but I never bothet to join that site. With regards to Ezine, I also heard about it and never took the chance to check it online. Hubpages, based on some reviews from people I knew, they talk more about it. While I rarely see people talkinh about Ezine. So I suggest Hubpages because of its popularity. However, I don't disregard the benefits you can get from Ezine.