The main reason I like Wordpress is so many online hosting companies have it as a platform, so it is easier to transition from Wordpress.com over to your own domain if/when one decides to do so. Wordpress has gotten much easier to manage through the years. That said, when I get a domain, I make sure I also grab the names at Wordpress and Blogger, to better control the name. So, whichever you decide, I would make sure you get the same name at the other, if possible.