There are benchmarks around [1], though I consider them valuable only for the entertainment value.
The great thing about uWSGI/Nginx over Gunicorn/Nginx is that Nginx speaks the uwsi protocol natively[2], whereas with Gunicorn Nginx acts as a proxy.
Also, in my experience (2 years with gunicorn, 1 with uwsgi in prod), uwsgi is more stable, uses less memory, has better management and configuration tools and even lets you run multiple Python apps under the same intepreter (multitenancy) [3].
The great thing about uWSGI/Nginx over Gunicorn/Nginx is that Nginx speaks the uwsi protocol natively[2], whereas with Gunicorn Nginx acts as a proxy.
Also, in my experience (2 years with gunicorn, 1 with uwsgi in prod), uwsgi is more stable, uses less memory, has better management and configuration tools and even lets you run multiple Python apps under the same intepreter (multitenancy) [3].
[1] http://www.peterbe.com/plog/fcgi-vs-gunicorn-vs-uwsgi
[2] http://wiki.nginx.org/HttpUwsgiModule
[3] http://projects.unbit.it/uwsgi/wiki/TipsAndTricks
(Edit: formatting)