I work for a cloud service provider, and we use Chef in a heterogeneous environment. Several flavors of Linux, and Windows 2003-2012 (both 32 and 64 bit). The pretty is that Chef supports Windows very well, and the mature community cookbooks have good support for Windows as well. The ugly is that it makes testing more complex, but things like ChefSpec and ServerSpec + TestKitchen and Jenkins make it possible to release robust code.
The other CM software may have good Windows support as well, but I don't have any direct experience with it. Either way, the testing is the more critical component here, no matter what CM platform you choose.
ChefSpec and Test-Kitchen are really awesome. I tend to see Chef as a framework for automating infrastructure, not as a scripting language/environment to define resources.
Chef pays off in large scale infra or highly dynamic environments but chef-solo is still a bit lame (I juse knife-solo for that[1]). So most people seem to start with no-devops, shellscripts, puppet/ansible… later they will understand why there are more complex/flexible solutions out there.
It also depends on the background of the DevOps people: Coming from software engineering, you're probably familar with concepts like DRY, YAGNI and principles of clean and robust code. However when your team consists of people with admin-background, they have probably no experience and will write very bad code especially in less strict scripting languages. They are probably happier and more productive with strict configuration files (e.g. YAML) but in the end, they need to start programming…
The other CM software may have good Windows support as well, but I don't have any direct experience with it. Either way, the testing is the more critical component here, no matter what CM platform you choose.