I prefer WordPress because it is extremely easy to use, with a flexible architecture (via plugins) which can be used to add more handy features on your blog.
Having a self hosted WordPress blog allows you the freedom to use whatever design theme you need but also to fully customise your website.
In terms of Blogger getting more traffic this is expected as it is a Google product and the Google search results always favour Google products. However with a bit of preparation on your WordPress blog you can bring a lot of traffic if your content is interesting enough.
Let me know if this helps.