That is a great question, and I am using both for some of my blogs and sites.
Blogger:
Pros - Free and instant indexing into the google search engine results.
Cons - limited to what you can do for layout without extensive knowledge of the blogger system, limited comments system, limited with just about anything you can think of that you might want to customize as your own.
Wordpress.org install:
Pros - you can do whatever you want, install any theme you want, any plugins, etc...etc...etc...
Cons - will need your own server and domain name so there is a cost with that, maybe need some coding experience to work out any bugs, or know how to get around with directions.
I hope that helps a little bit. I use both for several sites that I have, and I like wordpress better as it allows me more control over the site. Blogger is a good system too, don't get me wrong, and maybe I'm not completely familiar with the inner workings of it.
_________________
Insurance reviews