Config management tools are awesome, if you've got enough servers to warrant the learning curve, the "chicken and egg" problem with getting the config management tool installed in the first place, AND if you can get your entire sysadmin team on board with consistently using the tool and only the tool for any changes.
If you've only got a few servers, or if you've got a very heterogeneous environment.. then they might not be worth it. If you've got a lot of servers, config management tools may save your life.
The tools do keep improving though, and Puppet and Chef are miles ahead of earlier tools and even every commercial tool I've yet seen. But this is still an area with a lot of opportunity for innovation.
If you've only got a few servers, or if you've got a very heterogeneous environment.. then they might not be worth it. If you've got a lot of servers, config management tools may save your life.
The tools do keep improving though, and Puppet and Chef are miles ahead of earlier tools and even every commercial tool I've yet seen. But this is still an area with a lot of opportunity for innovation.