My company is creating a service in an Amazon Virtual Private Cloud. Without getting too much into the details, there will be about 5 different types of servers, and each type will need to be replicated based on demand. A bit of reading gives me the impression that we're going to want to use a config management tool like Puppet or Chef.
My bosses are receptive to the idea, but need convincing that it's actually worth the upfront cost of learning one of these tools. I have no experience with these tools, and can't really offer anything other than a few bullet points on what they do, and that wiser people on the internet seem to think it's a good idea.
The benefits of a CM just seem like vague best practices at this point, since I haven't yet experienced the problems that they are meant to solve. What headaches can I expect if we don't use a config management tool?