In my opinion Blogger or Wordpress can be ranked just as well in the SERPS. In my experience the only difference is that blogger sends more referral traffic. I use both Wordpress and Blogger and have never noticed a difference in the time it takes to get ranked for certain keywords.
Blogger is one of the most popular free blog services. They have quite a few features and offer the ability to export your site or host it on your own domain in the future. A new post on Blogspot is usually indexed within minutes if the blog is a few weeks old.
We have recently gotten into Wordpress development and have only good things to say about the platform. A large community of coders creating great themes and plugins. Either will get crawled quickly if using something like Pingomatic.