Running Django with Gunicorn - Best Practice

There are 3 ways to run a django application with gunicorn:

1. Standard gunicorn + wsgi (ref django doc)

   gunicorn project.wsgi:application

2. Using gunicorn django integration (ref gunicorn doc and django doc):

   python manage.py run_gunicorn

3. Using gunicorn_django command (ref gunicorn doc)

   gunicorn_django [OPTIONS] [SETTINGS_PATH]

Django's documentation suggests using 1., which is not even listed as an option on Gunicorn documentation.

Is there any best practice on the best way to run a django app with gunicorn, and what are the foreseable advantages/disadvantages of these different solutions?

Taking a glimpse at gunicorn's code it looks like they pretty much all do the same: 2. seems to be creating a wsgi app using django's internals, and 3. uses 2.

If that's the case, I wouldn't even understand what's the reason for not simply using "1." all the time, especially since a wsgi.py file is autocreated for you since django 1.4; if that's true maybe simply a documentation improvement should be suggested...

Also, best practice for gunicorn settings with django would be great. Using 1., does it make sense to set some defaults in the wsgi file and avoid additional settings?

References: