Obsolete before it hit 1.0. While grunt/gulp was fun for a while... i am not looking back to our 800 line grunt file, complicated async configuration and the tons of dev-dependencies. Webpack blew everything out of the water. 80 lines of config, hot-reloading, code-spliting, hash-filenames... Looking forward to whats coming next.
The docs are very basic and there are so many configuration params.
If you want to do something that's not covered in tutorials or boilerplates, be prepared to spend a ridiculous amount of time reading Webpack PRs, issues and the codebase.
Webpack does a great job and it's a nice concept but it has very bad documentation.
[1] Isomorphic apps, or multiple builds for i18n etc