Notice: there is a lot of theoretical questions.

Recently I'm reading about Puppet (and similar systems), which - as I believe - can make my work easier, a lot. But I try - and unfortunately can't - to understand what all I can "puppetize". I can imagine "clouds" or HA clusters, where is the same config on more servers. But what about workstations? I have one pc (centos with kvm), one notebook (fedora) and personal server, can (or should) it be puppetized? What are (dis)advantages? Or in our company we have hundreds of servers (mainly with centos), but each of them is a little bit different. Can't decide if it's better to have a lot of configs on one place.. (Dis)advantages? I will be happy for all your opinions or links with this topic.