[ljm]

I find it most handy for debugging, especially if you've got the sourcemaps available (infinitely easier without minified code though). In that sense the developer console is an underutilised tool when trying to nail down problems, especially in highly stateful SPAs and I tend to use it as a REPL before I start putting pen to paper in my editor. So much easier than trying to create the ideal state locally if you already have it handy somewhere else.

Although I notice in general that this style of development (or its close friend REPL-driven development) is hard to teach for people heavily accustomed to print debugging or even TDD.