The sky is the limit, node-webkit is indeed very powerful when you know what you're doing.
For the build process: just try it with brunch, e.g.: with my skeleton (a simple todo app is included for playing around). It will take ~4sec to start up initially, but then work close to perceived realtime, taking 50ms or so on my machine to reflect any changes you do, plus: livereload automatically the browser window, so you actually save the "press reload" step in most cases.
And: since i'm using only meta-languages that require a compile-step (!), i have basically a useful error-checking (incl. linting!) on coding time, without time-intensive inspecting the result in-browser. Do not underestimate this. Sure, finally i have to confirm in the browser (and/or testsuite) that everything works, but typos and other common bugs are "growled" as i type.
Absolutely. But don't overestimate it either! Most serious bugs compile perfectly well -- and so you're trading quick detection of simple errors for more difficulty dealing with the hard stuff.
The nice thing is, that brunch automatically generates proper sourcemaps, so you can debug your application pretty well. Soooo, you have the little stuff catched instantly and are able to debug higher-abstraction code (!) without much hassle. Of course, this just works in my specific case that simple... :)
For the build process: just try it with brunch, e.g.: with my skeleton (a simple todo app is included for playing around). It will take ~4sec to start up initially, but then work close to perceived realtime, taking 50ms or so on my machine to reflect any changes you do, plus: livereload automatically the browser window, so you actually save the "press reload" step in most cases.
And: since i'm using only meta-languages that require a compile-step (!), i have basically a useful error-checking (incl. linting!) on coding time, without time-intensive inspecting the result in-browser. Do not underestimate this. Sure, finally i have to confirm in the browser (and/or testsuite) that everything works, but typos and other common bugs are "growled" as i type.