I've once created a profile with about 1500 lines of code for powershell, managing AD at work. It was great to learn, it's great for scripting and it's very intuitive (for me at least), I also liked working with objects.
I wouldn't use it on Linux though, I'm not sure how well integrated it is.
I'm using fish at the moment, desktop and server, and I like it primarily for the functions and the autocomplete