I used fish for a while (and really enjoyed it, it's a great shell), but it's formatting is too inconsistent with bash for me. I found myself dropping back to zsh so often to write documentation or run a playbook that I switched back.
If you often share shell code with others it may be to big of a leap for you.
If you're running a script, you can use edc/bass to run it from a fish shell. Fisher is one of the first things I install after fish, then bass, z and a few other helper plugins.