We've been pretty happy with it at Pathwright. 1.7 was a great release. The conventions aren't too restrictive, and it has been incredibly easy to get contractors plugged in and productive in minimal time. We follow many best practices, so our codebase is going to be "familiar" (to some extent) to anyone with some experience. We love Django for the productivity level our team achieves with it.
The ecosystem is great, too. django-rest-framework in particular makes us oh-so-happy.
Not to knock flask/Pyramid/everything else. Pick what your team can be most productive wit. I just think there are less reasons than ever to get too caught up in choice of framework. There are so many great options now.