Anyway, Ansible has been great for small/medium sized projects. I haven't used it for anything large, so I can't really speak if you're planning on working on big projects. I was able to pick it up in a day, and after a few days I felt I was comfortable with it. For me, copying parts of other people's playbooks from Github and trying to understand it was the best way to learn after getting an overview from the documentation. Just start with something small - like installing & configuring a database, and work your way up the stack. Can't speak to any other dev-ops tools since Ansible is the first I've learned, but I've been happy with it.
I'm sticking with ansible for certain and I'm happy about it.
Here's about a dozen ansible "roles" I've created if you want to poke around the code. They are all tested with travis ci too.
https://github.com/nickjj/orats#ansible-roles-used
It's geared towards deploying a rails app but a lot of it is neutral and the rails role itself could be adjusted for django/etc. without much work.
There was a talk recently where a dude from twitter explained how they are using ansible to deploy many thousands of services so I'd say it scales.