I work as a Windows device driver developer, and sometimes I need to reverse engineer some of the internals, and the source code from WRK is easily available on the internet : (http://gate.upm.ro/os/LABs/Windows_OS_Internals_Curriculum_R...). These are sources from 2005-2006 timeframe, but they are tremendously helpful when debugging. If you compare the disassembled version of an exported function from the Win 8.1 ntoskrnl, in most cases it's almost identical to the sources in those links. Of course, there are a few parts of the system which suffered changes, but nonetheless, it can still be very useful.
I would also recommend it for studying operating systems, but obviously, along side something else. Let's say after starting with XV6, or Pintos, Minix, then moving on to NetBSD, Linux, only after that having a look under the hood of Windows, to see a slightly different approach.
There is also the 'Windows Internals' book, but I never found it too useful. Describing concepts without any source code, and without a view to the implementation is not very helpful for me.
But I completely agree with you, personally, I would never use Windows if I wanted to play with it, I only use linux and bsd at home.