I use Nix and it's awesome, but still in early adopter territory. It works wonderfully if you really value reproducible builds and are willing to put some effort in the initial setup, but it's still a bit fiddly and documentation is nearly non-existent. If you have the time and motivation to learn about it up-front and get it set up it pays off, but I wouldn't recommend it to beginners just trying to learn Haskell.