[wklauss]

More than usable. For the majority of users I'd say it is a better option, not as resource-hungry as Chrome or chromium based browsers.

[TheRealDunkirk]

And, while I'm not a hard-core JS programmer, I've found Safari's dev tools to be just as good as Firefox's or Chrome's.

[andrethegiant]

Same! I prefer Safari dev tools for inspecting the DOM, CSS prototyping, debugging, seeing request/response headers, local storage info. I use it every day, and find its interface much more intuitive and way less bloated. However Chrome devtools are better when it comes to performance profiling, and having extensions like React devtools make me wish that was a capability of Safari.