To set up initially, possibly. But this is for maintenance too. Need to install a security patch? Puppet. Need to upgrade versions? Puppet. Want to tweak some setting somewhere? Puppet. Using Puppet makes it stupid easy for us to keep our setups (a) in sync, (b) up to date and secure, and (c) do it without a bunch of hacky scripts that will probably break or not work right in 3 months.