1) You can transfer your Blogspot blog to a fresh domain by the mere click of a button. 2) You can also transfer the hosting to a new hosting service at the mere click of a button. 3) You have access to the HTML source code and so you can do pretty much anything you desire in regards to customisation, SEO etc. Maybe you should have done your homework hey? What makes me laugh about you Wp fanboys is that your more than happy to slag off Google's amazing blogging platform and yet 90% of you no doubt rely on the very same company to bring in all your traffic. *****
I would go towards WordPress in my personal opinion. Far many more options than Blogger but if you are just starting out you can definitely earn from Blogger. Don't let anyone say you can't earn from a Blogger since I was earning a steady $1 a day on a Blogger blog.
Wordpress by a far margin! Why? Because: - you can customize your blog a lot - there are tons of themes and plugins
I like and use both. I have a number of Blogger blogs that have been very successful (adsense) compared to the amount of time and effort I've put into them. But, at the end of the day, I prefer WP hosted on a server. While you can transfer or install a blogger blog from Google to a self hosted account, I always felt that the WP plug-ins were the deciding factor. Just my .02 worth.
I much prefer Wordpress and it seems to rank much much better for me than blogger. I still use both of them .