You can double click items to edit them or add pages directly on the website (as long as you're logged in as admin). It simplifies content creation and touch-ups.
Documents are organized in a tree. You can either create new content area type, new tree nodes, integrate complete existing Django app in the tree, etc. It's pretty easy usually.
Having a website in more than one language can be very challenging and DJango-CMS supports it well. Switching between languages while keeping on the page for example.
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.
Although Wagtail comes with only the most basic features, it's by no means an incomplete CMS. It's very extendable and it's up to the developer to choose how to extend it.
Wagtail has the perfect separation between developers and editors. It allows you to construct a site with minimal fuss with features like the awesome stream field and hand it over to virtually any content editor. You can build the site with no knowledge of Django and with the simple interface require no training to get started.
Although this will always require developer time, with 2 or 3 days you can quickly get up a boilerplate site that will fulfill 80% of any site you will develop. Leaving only the bespoke parts to do.
It also nicely slots into any Django project with no fuss.
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.
Editing of blog posts or themes and widgets can be done on the frontend as long as the user is logged in with an Admin account. This make Mezzanine very easy to use and manage even for people who may not be experienced at all in programming.
Mezzanine is a very well-maintained CMS. It is very popular and has a nice and helpful community around it. This means that there's help available for any problem that you may face with it.