The Arch wiki is great. Reminds me of the old Gentoo wiki from way back when Gentoo was the new hotness. I'm not even an Arch user but documentation as to how things like Window Managers work is fantastic.
In my experience, the first step in trying out a new system is installing it, configuring everything (from network connectivity to various peripherals), installing your favorite software and so on.
This gives a good idea on how to work with the system, how good the documentation is (as another poster already mentioned), how simple and consistent everything is.
Installing in a VM is not the best differentiation, since in many OSs these experience was streamlined and everything usually works out of the box, but the customization part is still a good example.
Of course in the end, you might get to a setup similar to other OSs - running a browser in a windows manager and a buch of other common tools (IDEs, editors, productivity apps), but the way you get there, and the amount of problems you encounter along the way is a major part of using an OS.
I think you can get a good impression in a few hours, and see how it's different. (For example, I had a similar experience with NixOS: In a few hours you see how radically different it is and learn how it fits you)
