Django CMS project is a large and complex project, comparable to Wordpress. As such, it may be too much for a simple personal blog considering that it has many features that may never be used in that particular occasion.
Installing Wagtail on a remote server is a little more complicated than FTPing a bunch of files. Furthermore there's no ecosystem for plugins and themes so it can only be fully extended by a developer experienced with Django.
Mezzanine has a built-in search engine and API, integration with services like Disqus, Gravatar, Google Analytics, Twitter, bit.ly, Akismet, a blog and a good selection of templates available out of the box.