I think it's important to note where these frameworks come from. Rails started as a means to build a web app. Django started as a CMS for online newspapers.
I toyed with Django for a while before I moved to Rails. The main force driving me to Django first was that I already knew Python, whereas I'd never really used Ruby. I chose Rails over Django because of the magic. It seemed like I had to learn a lot more up front to get a web app working in Django, where I could get things working first in Rails while learning what the framework is doing over time.