I do not know about how quickly search engines crawl wordpress blogs or blogger blogs, but I do know that after only seven days and no
SEO except adding a few tags
my wordpress blog is getting 3-15 views a day and Google is listing it. I originally had
this blog hosted on blogger for about 10 days and I do not think that I got more than one visit the whole time. However, do not think that I prefer Wordpress. My other blog,
Build Your Own Ecommerce Website!, has been hosted on Blogger for about 2 months and it is getting about 30 visitors everyday. The main reason that I like Blogger is because they will let you sell things on it. Wordpress blogs will not unless it is self-hosted. Anyway, those are just my thoughts.
Hope this helps!