I've just installed fish and it doesn't support bang (!) history nor some basic scripting tools (eg $?) which makes it pretty useless for power users.

I can see how the colours and suggestions are great to those who are new to the command line though and there were some cool features (eg highlight search phrases from grep). But most of that stuff is just emphasising stuff you'd learn to spot anyway, after using the CLI for years.

So as cool as it is, I really would find it more of a hindrance than a help.