I'm looking to install a different unix on my workstation to acquire some perspective on GNU/Linux and out of curiosity. I have narrowed my options down to these two. The reason for considering PureDarwin is because I have very little experience with Apple's products.
So my question is will installing and using PureDarwin give me a closer understanding of OSX than would running FreeBSD? What I have in mind are day to day routines like adding users, installing software and configuring various aspects of the underlying OS. I know that the GUI of OSX would not be available, but that is not a concern.
As a secondary, less important question, can I buy OS X in the apple store and run it in a virtual machine or does that violate their EULA?