Well, ansible by default runs with paramiko which is a python implementation of SSH protocol. It will also keep connections open for multiple commands. It also has a pull mode and it also has a fireball mode which uses 0mq:

http://jpmens.net/2012/10/01/dramatically-speeding-up-ansibl...

However, you're not forced to use this. In the beginning, you can just seed your CentOS or debian with a Kickstarter or seed file and then run your inital thing with ansible simply over ssh (using all the goodies, ssh-agent, password less ssh etc..).

One huge plus for ansible is also that it used yaml which is rather simple. I've been following both project for >1 year and it seems that recently ansible has picked up a lot and will probably make the "race" (IMO).