Copyrights and Ownership of Content
With the free site ( blogger and wordpress.com ), Google and Wordpress Owns Your Content
Google has the authority to shut down your account without warning if they don’t like what you’re blogging about. You don't have absolute control over your own blog.
Self-hosted Wordpress :
With Wordpress, you own the domain name and the blog is hosted on your own account. You have full control over your content. With the self-hosted version of Wordpress (not the free Wordpress.com), you're free to write about anything you want, and use the software in any way you want.
Yes, Blogger allows you to publish to your own domain, but they still own the database that holds your content! Don't forget that!
Search Engine Optimization and Traffic
There's this propaganda that since Google owns Blogger, they tend to favor Blogger accounts. I won't say that this is illogical, but from my experience, there's no such favoritism.
I've heard as many stories of getting indexed fast and ranking high in search engines from both Wordpress and Blogger users. As long as the content is good, the spiders will come.
When you post in Blogger, you can only “ping” a limited amount of sites, whereas with Wordpress on your own domain you can ping as many blog directories as you want, and start getting more traffic.
As a conclusion, I would say that Wordpress is only slightly ahead in terms of optimization for search engines, and building large amounts of traffic.
A very important factor in our online experience as webmasters is the index time. Well BLOGGER wins this time because it has a big advantage: it’s hosted on google servers. The result is incredible: start a new blog and you’ll get indexed in less then 24 in Google (provided you have the content !)
Yes this is a true and tested thing. The Wordpress site is just another website from the search enine point a view but on Blogger, it gets some extra points for being a blog.
From the postings, I still like blogger ! Happy Blogging !