A simple HTML form to "arm" the installation server, a simple reboot and PXE booting can be much more effective than all the painkillers combined for remedying the headaches of IT people and managers alike.
If you don't roll changes that often, you can distribute emergency USBs to install servers and workstations. Even a single USB can detect and install the system accordingly.
Of course we should point out sucky tools regardless of its platform.
I feel the need to sing, "You may have both.... you _may_ have both.... it's not so hard to imagine... MS even did it in certain products..."
Being able to tune a system from top to bottom solely with text files is just amazing. Also, some people hate "everything is a file" philosophy, but it's the enabler of this configurability.
When I started programming Linux and saw that everything was accessible via normal file system, it was a big relief compared to W32's iceberg environment, where you cannot see everything and sometimes water is too cold to dive that deep.
When you start to administer hundreds or thousands of servers, scriptability of CLI tools and pliability of text files trumps all computer automation.
xCAT and Salt are two tools (that I use regularly) which are built on these properties and can manage thousands of servers with a "flick of a finger".