While the release of Component 1.0 solved a lot of the initial gripes with earlier versions of Component, in the end we were after a more radical departure from Component that borrowed some good ideas from Browserify.
Browserify is a great project and if it's working well for you then you should keep using it.
Duo's scope is much more ambitious. Duo aims to be your go-to asset pipeline for Node.js. Much in the same way that Sprockets is for the Ruby community.
Browserify's dependence on NPM to deliver it's packages leads to some big issues:
- naming is a bigger hassle on the client-side (how many different kinds of tooltips are there?)
- private modules require a private NPM server
- ensuring your team has push access to each module is always a pain, especially when a teammate leaves
By using GitHub as your package manager all of these issues disappear.