I tried that initially but never spent enough time using it in a VM to really learn it.
In the end, I just decided to take the plunge and set it up as my main OS after a year of procrastinating around trying it out. I've been using it for about 4 years now, and wouldn't go back to a traditional distro.
And finally, 4 years on, I just set up a new laptop and it was much easier than its ever been before. I just had to copy over my existing nix config, and nix built out the whole configuration and my user environment (with home-manager [0]). It's always been a bit of a pain setting up my profile before this, and maintaining my .emacs.d, etc; now it's all managed.
[0] https://github.com/rycee/home-manager