Packstack is a utility that can be used to deploy openstack on multiple hosts, It makes use of the various puppet modules on stackforge (by including them as git submodules.

The answer to your question depends on exactly what you want to deploy, for a test openstack deployment or a relatively small production deployment packstack will fit your needs. You'll find some packstack information on RDO site.

On the other hand for larger deployments where you need the configuration management advantages of puppet then using the puppet modules with puppet master is the way to go.