In general, I like Ansible's concepts of idempotency, etc., and find them to be well suited for server configuration in general, but it does come at a price, both in terms of development time and speed (I actually find Ansible to be a lot slower than Fabric).

I've started thinking of server configurations in Ansible terms (i.e. "I want X module installed, Y directory present, etc"), but sometimes nothing beats a simple bash command to git pull && sudo service restart.